React and its component structure
● What are Hooks?
● React Hooks and their capabilities
● Migrating Your Existing Apps to React Hooks
● Combine Existing React Hooks into New Custom Hooks
● Benefits of using React Hooks
● Best Practices
Spinners, Adapters & Fragment CommunicationCITSimon
How to incorporate Spinners into your Android App and populate them using Adapters.
The second half of this lesson details the basics of how to make fragments communicate with each other within an Android App.
Provide an object as a surrogate for the lack of an object of a given type. The Null Object provides intelligent do nothing behavior, hiding the details from its collaborators.
Originally written up by Bobby Wolf, in Pattern Languages of Program Design 3
React and its component structure
● What are Hooks?
● React Hooks and their capabilities
● Migrating Your Existing Apps to React Hooks
● Combine Existing React Hooks into New Custom Hooks
● Benefits of using React Hooks
● Best Practices
Spinners, Adapters & Fragment CommunicationCITSimon
How to incorporate Spinners into your Android App and populate them using Adapters.
The second half of this lesson details the basics of how to make fragments communicate with each other within an Android App.
Provide an object as a surrogate for the lack of an object of a given type. The Null Object provides intelligent do nothing behavior, hiding the details from its collaborators.
Originally written up by Bobby Wolf, in Pattern Languages of Program Design 3
Automatic reference counting (arc) and memory management in swiftInnovationM
Memory management is a key factor when we developing apps. If a program is using a lot of memory it can affect badly on your device making apps run slowly or even cause crashes. So for that in swift, you can work with Automatic Reference Counting (ARC) to keep your apps memory usage minimal. This doesn’t mean you can forget about the memory in your app but it does take care of most things for you.
GUI Programming in JAVA (Using Netbeans) - A ReviewFernando Torres
The powerpoint provides the user with a review of various concepts of GUI programming in JAVA. It covers various concepts like :
1. What is IDE ?
2. Various Methods and Properties of Components
3. Variable declaration
4. Data types
Etc
Static Keyword Static is a keyword in C++ used to give special chara.pdfKUNALHARCHANDANI1
Static Keyword Static is a keyword in C++ used to give special characteristics to an element.
Static elements are allocated storage only once in a program lifetime in static storage area. And
they have a scope till the program lifetime. Static Keyword can be used with following, Static
variable in functions Static Class Objects Static member Variable in class Static Methods in class
Static variables inside Functions Static variables when used inside function are initialized only
once, and then they hold there value even through function calls. These static variables are stored
on static storage area , not in stack. void counter() { static int count=0; cout << count++; } int
main(0 { for(int i=0;i<5;i++) { counter(); } } Output : 0 1 2 3 4 Let\'s se the same program\'s
output without using static variable. void counter() { int count=0; cout << count++; } int main(0
{ for(int i=0;i<5;i++) { counter(); } } Output : 0 0 0 0 0 If we do not use static keyword, the
variable count, is reinitialized everytime when counter() function is called, and gets destroyed
each time when counter() functions ends. But, if we make it static, once initialized count will
have a scope till the end of main() function and it will carry its value through function calls too.
If you don\'t initialize a static variable, they are by default initialized to zero. Static class Objects
Static keyword works in the same way for class objects too. Objects declared static are allocated
storage in static storage area, and have scope till the end of program. Static objects are also
initialized using constructors like other normal objects. Assignment to zero, on using static
keyword is only for primitive datatypes, not for user defined datatypes. class Abc { int i; public:
Abc() { i=0; cout << \"constructor\"; } ~Abc() { cout << \"destructor\"; } }; void f() { static Abc
obj; } int main() { int x=0; if(x==0) { f(); } cout << \"END\"; } Output : constructor END
destructor You must be thinking, why was destructor not called upon the end of the scope of if
condition. This is because object was static, which has scope till the program lifetime, hence
destructor for this object was called when main() exits. Static data member in class Static data
members of class are those members which are shared by all the objects. Static data member has
a single piece of storage, and is not available as separate copy with each object, like other non-
static data members. Static member variables (data members) are not initialied using constructor,
because these are not dependent on object initialization. Also, it must be initialized explicitly,
always outside the class. If not initialized, Linker will give error. class X { static int i; public:
X(){}; }; int X::i=1; int main() { X obj; cout << obj.i; // prints value of i } Once the definition for
static data member is made, user cannot redefine it. Though, arithmetic operations can be
performed on it. Static Member Functions These functions work for the .
“Lambdas in JAVA 8 is not for what they can do, It is about how we write Program”
It enables Functional Programming, It Adds a New nucleotides in the DNA of Java.
There is a Change in “The Climate” to change our Ways.
Automatic reference counting (arc) and memory management in swiftInnovationM
Memory management is a key factor when we developing apps. If a program is using a lot of memory it can affect badly on your device making apps run slowly or even cause crashes. So for that in swift, you can work with Automatic Reference Counting (ARC) to keep your apps memory usage minimal. This doesn’t mean you can forget about the memory in your app but it does take care of most things for you.
GUI Programming in JAVA (Using Netbeans) - A ReviewFernando Torres
The powerpoint provides the user with a review of various concepts of GUI programming in JAVA. It covers various concepts like :
1. What is IDE ?
2. Various Methods and Properties of Components
3. Variable declaration
4. Data types
Etc
Static Keyword Static is a keyword in C++ used to give special chara.pdfKUNALHARCHANDANI1
Static Keyword Static is a keyword in C++ used to give special characteristics to an element.
Static elements are allocated storage only once in a program lifetime in static storage area. And
they have a scope till the program lifetime. Static Keyword can be used with following, Static
variable in functions Static Class Objects Static member Variable in class Static Methods in class
Static variables inside Functions Static variables when used inside function are initialized only
once, and then they hold there value even through function calls. These static variables are stored
on static storage area , not in stack. void counter() { static int count=0; cout << count++; } int
main(0 { for(int i=0;i<5;i++) { counter(); } } Output : 0 1 2 3 4 Let\'s se the same program\'s
output without using static variable. void counter() { int count=0; cout << count++; } int main(0
{ for(int i=0;i<5;i++) { counter(); } } Output : 0 0 0 0 0 If we do not use static keyword, the
variable count, is reinitialized everytime when counter() function is called, and gets destroyed
each time when counter() functions ends. But, if we make it static, once initialized count will
have a scope till the end of main() function and it will carry its value through function calls too.
If you don\'t initialize a static variable, they are by default initialized to zero. Static class Objects
Static keyword works in the same way for class objects too. Objects declared static are allocated
storage in static storage area, and have scope till the end of program. Static objects are also
initialized using constructors like other normal objects. Assignment to zero, on using static
keyword is only for primitive datatypes, not for user defined datatypes. class Abc { int i; public:
Abc() { i=0; cout << \"constructor\"; } ~Abc() { cout << \"destructor\"; } }; void f() { static Abc
obj; } int main() { int x=0; if(x==0) { f(); } cout << \"END\"; } Output : constructor END
destructor You must be thinking, why was destructor not called upon the end of the scope of if
condition. This is because object was static, which has scope till the program lifetime, hence
destructor for this object was called when main() exits. Static data member in class Static data
members of class are those members which are shared by all the objects. Static data member has
a single piece of storage, and is not available as separate copy with each object, like other non-
static data members. Static member variables (data members) are not initialied using constructor,
because these are not dependent on object initialization. Also, it must be initialized explicitly,
always outside the class. If not initialized, Linker will give error. class X { static int i; public:
X(){}; }; int X::i=1; int main() { X obj; cout << obj.i; // prints value of i } Once the definition for
static data member is made, user cannot redefine it. Though, arithmetic operations can be
performed on it. Static Member Functions These functions work for the .
“Lambdas in JAVA 8 is not for what they can do, It is about how we write Program”
It enables Functional Programming, It Adds a New nucleotides in the DNA of Java.
There is a Change in “The Climate” to change our Ways.
There are a lot of interesting facts that are still unknown and make the Javascript the world's most confusing language. I've tried to explain a few of them if they can help you in better understanding of the JS code.
Short answers ·GUI elements Static methods and variables Overloading .pdfkamdinrossihoungma74
Seedless green grapes are sold in mess bags at Winn Dixie and typically consist of 3-5 bunches
per bag. Suppose the weight of these bags follows a normal distribution with a mean and
standard deviation based on the table to the right. Determine the probability that a randomly
selected bag will contain the value indicated below?
The randomly selected bag will contain 35.0 ounces (Bag weight in ounces µ = 27.2 = 4.8)
Solution
Normal Distribution
Mean ( u ) =27.2
Standard Deviation ( sd )=4.8
Normal Distribution = Z= X- u / sd ~ N(0,1)
a)
P(X > 35) = (35-27.2)/4.8
= 7.8/4.8 = 1.625
= P ( Z >1.625) From Standard Normal Table
= 0.0521
P(X < = 35) = (1 - P(X > 35)
= 1 - 0.0521 = 0.9479.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Top 10 Oil and Gas Projects in Saudi Arabia 2024.pdf
S.k
1. Static Keyword
The static keyword is one which has several meanings in C++ that I find very
confusing and I can never bend my mind around how it’s actually supposedto
work.
Static methods
Static method s has no instances. They are called with the type name, not an
instance identifier. They are slightly faster than instance methods becauseof this.
Static methods can be public or private.
A static class is basically the same as a non-static class, but there is one difference:
a static class cannot be instantiated. In other words, you cannot use the new
keyword to create a variable of the class type. Because there is no instance
variable, you access the members of a static class by using the class name itself.
For example, if you have a static class that is named Utility Class that has a public
method named Method, you call the method as shown in the following example:
UtilityClass.MethodA();
Example
This program defines both static methods and regular instance methods. The static
methods use the static keyword somewhere in the method declaration signature,
usually as the first keyword or the second keyword after public.
Static: A static method cannot access non-static class level members. It has no
"this" pointer.
Instance:An instance method can access thosemembers, but must be called
through an instantiated object. This adds indirection.
2. Static keyword
We have been using static keyword in our examples. What is the meaning of
static? The word refers to something that is stationary, stopped and not moveable.
What are the types of these variables, declared as static?
How can we make use of them? Static as the word implies are variables which
exist for a certain amount of time, much longer than that by ordinary automatic
variables. Let’s consider the example about the lifetime of data variables.
One of the variable types is global variable. Global variables are those that are
defined outside of main. They are written as standalone statements before main
function as
int i; the variable ‘I’ is a global variable. It is not only accessible in main but also
in all the functions. They can assign some value to ‘I’ or obtain the value of ‘I’.
Global variables come into existence whenever we execute the program and the
memory is allocated for ‘I’. It exists all the time when the program is running. At
the end of the program execution, the memory will be de-allocated and returned to
the operating system. So it has a very long lifetime. We need a value which exists
for the complete execution of the program and is available in all the functions. We
use global variables. It is not a good idea to do that unless it is absolutely
necessary. The major plus point of these variables is that these are accessible from
everywhere in the program. The inconvenience is that these variables are visible in
those functions too which does not need them.
Suppose, we have a global variable ‘I’ declared as int i; and in some function we
are writing a for loop as for (i = 0; i < n; i++); Now which ‘I’ is being used here.
This is the variable ‘I’, declared as global. This global ‘I’ may have some valuable
value, like the number of cars or the number of students etc. Here, in the function
when we run the loop, the value of ‘I’ will be changed. The global variables have
this bad habit of being around, even when we don’tneed them. What will happen if
we declare another ‘I’ variable inside the function? A local variable will be created
inside the function at run time and the global ‘I’ is not going to be accessible. But
3. this can be very subtle and hard to track programming errors. These are not syntax
errors but logical ones. So beware of using too many global variables. Now have a
look on the other side of the picture. While writing functions, we pass values to
them. So instead of passing the value of ‘I’ again and again, we declare it as
global. Now it is available in the function, leaving no need of passing it.
Let’s now come to the next variety of variables. The variables, defined in the main
function are local to the function main. It means that they are accessible in all parts
of the main function. Their values can be assigned, used in computations and later
displayed. When we enter some function other than main, these variables are not
accessible there. They are hidden. The global and the local variables, declared in a
function are visible. The arguments passed to a function, are also visible. We pass
the parameters through stack. Parameters are written on the stack. Later, the
function is called which reads from the stack and makes a temporary copyfor its
use. The variables, declared and used inside the function are called automatic
variables. They automatically come into being when the function is called. When
the function finishes, these variables are destroyed. So automatic variables are
created constantly and destroyed all the time. Here, we are talking about variables
ordinary as well as user defined objects. Their behavior is same. They are
automatic when the function is called; memory is allocated normally on the stack
at the same time and used. When the function exits, these variables are destroyed.
What happens if we want that when the function exits, some value, computed
inside the function, is remembered by the function and not destroyed? This should
not be visible by the other parts of the program.
Let’s consider the example of a refrigerator. When we open the doorof a
refrigerator, the light turns on and we can see the things inside it. However, on
closing the door, the light turns off. Do we know that light is off because whenever
we open the doorthe light is on. When we close the doorwhat is inside. We do not
know. May be things magically disappear. When we open the door, magically, the
things are at their position. You can think of this like a function. When we enter in
the function, these automatic variables are available there and visible. When we
came out of the function, it is like closing the doorof the refrigerator and the light
is turned off. We cannot see anything. Function goes one step ahead of this and it
actually destroys all the variables. Whereas, in the refrigerator, we know that
things are there. Somehow we want the function to behave like that. Outside the
4. refrigerator, these things are not available. We can not access them. Let’s say there
is a bottle of water inside the refrigerator. You open the doorand place it some
other place. Next time, when you will open the door, the bottle is seen at the same
position where you have moved it. It would not have moved to some other
position. If you think of automatic variables, supposewe say inside the bodyof the
function int i = 0; Every time the function is called and you go into the function
where i is created. It has always the value 0 to start with and later on we can
change this value.
What we want is that whenever we go back into the function, once we call the
function like we open the doorof the refrigerator and move the bottle to some
other place and close the door. So we made one function call. Next time, when we
call the function, the bottle is found in its new place. In other words, if we have
defined an integer variable, its value will be set at 10 in the function when we
return from the function. Next time when we call the function, the value of that
integer variable should be 10 instead of 0. We want somehow to maintain the state
of a variable. We want to maintain its previous history.
If we declare a global variable, the state would have been maintained. The global
variable exists all the time. Whatever value is set to it, it is there and accessible
from any function. The drawback is that variable exists even when we don’t want
it. Static keyword allows us a mechanism from getting away of the downside of the
global variables and yet maintaining a state inside a function. When we visit, it is
found out what are its values before that we go ahead with this value. For this,
whenever we declare a variable inside the function, static keyword is employed
before the variable declaration. So we write as:
static int i;
That declares i to be a static integer inside the function. Think about it. Should we
declare static variables inside the main function? What will happen? ‘main’ itself is
a function so it is not illegal. There is no objective of doing this in main because
main is a function from where our programs start and this function executes only
for once. So its state is like an ordinary variable, declared inside main. It is only
relevant for the called functions. We write inside the function as static int i; while
initializing it once. It will be created only once irrespective of the number of
5. function calls. Now once it is created, we increment or decrement its value. The
function should remember this value. The programmer may go out of the function
and come back into it. We should get the value that should be same as that at the
time of leaving the function. It is necessary for the static variables that when these
are created, they should be initialized. This initialization will be only for once for
the complete life cycle of the program. They will be initialized only once.
Here, we have to take care of the subtle difference. In case of ordinary variable
declaration, we should initialize them before using. If you have to initialize an int
with zero, it can be written as int i; and on the next line i = 0; But in caseof static
variables, we have to use a different type of initialization. We have to use it as
static int i = 0; It means that creation of i and the allocation of memory for it takes
place simultaneously. It is initialized and the value 0 is written. This is
initialization process. If somewhere in the function, we have statement i = 10; it
will not be treated as initialization. Rather, it is an assignment statement. Here we
want that as soonas the variable is created, it should be initialized. This
initialization will be only for once for the lifetime of the program and it takes place
when first time we enter in to the function. However we can manipulate this
variable as many times as we want. We can increment or decrement it. However, it
will remember its last value. How does this magic work? So far, we have been
talking about the stack and free store. There is another part of memory, reserved
for the variables like static variables. On the stack, automatic variables are being
created and destroyed all the time. The heap or free store has the unused memory
and whenever we need memory, we can take it from there and after use return it.
This is the third part which is static memory area where static variables are created
and then they exist for the rest of the program. These variables are destroyed on the
completion of the program. So they are different from automatic variables which
are normally created on stack. They are different from dynamic variables that are
obtained from free store.
To prove this whole point let’s write a simple program to fully understand the
conceptand to see how this works. Write a small function while stating that static
int i = 0; Here, we are declaring i as a static integer and initializing it with zero.
Then write
6. i++; print the value of i using cout. Now this function just increments the value of
i. This i is a static integer variable inside the function. Now write a main function.
Write a loop inside the main and call this function in the loop. Let’s say the loop
executes for ten times. You will notice that whenever you go inside the function,
the value of i is printed. The value of i should be printed as 1.2.3…10. If you
remove the word static from the declaration of i, you will notice that every time 1
is printed. Why 1? As i is now automatic variable, it is initialized with zero and we
increment it and its value becomes 1. cout will print its value as 1. When we return
from the function i is destroyed. Next time when function is called, i will be
created again, initialized by zero, incremented by 1 and cout will print 1. By
adding the static keyword, creation and initialization will happen oncein the life
time of our program. So i is created once and is initialized once with the value of
zero. Therefore i++ will be incrementing the existing value. At first, it will become
1. In this case, function will return from the loop in the main program, call this
function again. Now its value is 1, incremented by 1 and now the value of i
becomes 2 and printed by cout. Go backto main, call it again and so on, you will
see it is incrementing the last value. You can prove that static works.