The document provides an overview of arrays in Java, including:
- Arrays can hold multiple values of the same type, unlike primitive variables which can only hold one value.
- One-dimensional arrays use a single index, while multi-dimensional arrays use two or more indices.
- Elements in an array are accessed using their index number, starting from 0.
- The size of an array is set when it is declared and cannot be changed, but reference variables can point to different arrays.
- Common operations on arrays include initializing values, accessing elements, looping through elements, and copying arrays.
This is a presentation on Arrays, one of the most important topics on Data Structures and algorithms. Anyone who is new to DSA or wants to have a theoretical understanding of the same can refer to it :D
This is a presentation on Arrays, one of the most important topics on Data Structures and algorithms. Anyone who is new to DSA or wants to have a theoretical understanding of the same can refer to it :D
Using various data structures: Using Arrays (One Dimensional, Two Dimensional,
Jagged), Array.
ArrayList classes
Using Collections: Collection, HashTable, List, Stack, Queue, HashSet classes.
Professional help with C programming assignments offered by expert programmers who will provide you thoroughly commented code and ensure you submit top notch work.
An Introduction to Programming in Java: ArraysMartin Chapman
An Introduction to Programming in Java: Arrays. Last delivered in 2012. All educational material listed or linked to on these pages in relation to King's College London may be provided for reference only, and therefore does not necessarily reflect the current course content.
Homework Assignment – Array Technical DocumentWrite a technical .pdfaroraopticals15
Homework Assignment – Array Technical Document
Write a technical document that describes the structure and use of arrays. The document should
be 3 to 5 pages and include an Introduction section, giving a brief synopsis of the document and
arrays, a Body section, describing arrays and giving an annotated example of their use as a
programming construct, and a conclusion to revisit important information about arrays described
in the Body of the document. Some suggested material to include:
Declaring arrays of various types
Array pointers
Printing and processing arrays
Sorting and searching arrays
Multidimensional arrays
Indexing arrays of various dimension
Array representation in memory by data type
Passing arrays as arguments
If you find any useful images on the Internet, you can use them as long as you cite the source in
end notes.
Solution
Array is a collection of variables of the same type that are referenced by a common name.
Specific elements or variables in the array are accessed by means of index into the array.
If taking about C, In C all arrays consist of contiguous memory locations. The lowest address
corresponds to the first element in the array while the largest address corresponds to the last
element in the array.
C supports both single and multi-dimensional arrays.
1) Single Dimension Arrays:-
Syntax:- type var_name[size];
where type is the type of each element in the array, var_name is any valid identifier, and size is
the number of elements in the array which has to be a constant value.
*Array always use zero as index to first element.
The valid indices for array above are 0 .. 4, i.e. 0 .. number of elements - 1
For Example :- To load an array with values 0 .. 99
int x[100] ;
int i ;
for ( i = 0; i < 100; i++ )
x[i] = i ;
To determine to size of an array at run time the sizeof operator is used. This returns the size in
bytes of its argument. The name of the array is given as the operand
size_of_array = sizeof ( array_name ) ;
2) Initialisg array:-
Arrays can be initialised at time of declaration in the following manner.
type array[ size ] = { value list };
For Example :-
int i[5] = {1, 2, 3, 4, 5 } ;
i[0] = 1, i[1] = 2, etc.
The size specification in the declaration may be omitted which causes the compiler to count the
number of elements in the value list and allocate appropriate storage.
For Example :- int i[ ] = { 1, 2, 3, 4, 5 } ;
3) Multidimensional array:-
Multidimensional arrays of any dimension are possible in C but in practice only two or three
dimensional arrays are workable. The most common multidimensional array is a two
dimensional array for example the computer display, board games, a mathematical matrix etc.
Syntax :type name [ rows ] [ columns ] ;
For Example :- 2D array of dimension 2 X 3.
int d[ 2 ] [ 3 ] ;
A two dimensional array is actually an array of arrays, in the above case an array of two integer
arrays (the rows) each with three elements, and is stored row-wise in memory.
For Example :- Program to fill .
Using various data structures: Using Arrays (One Dimensional, Two Dimensional,
Jagged), Array.
ArrayList classes
Using Collections: Collection, HashTable, List, Stack, Queue, HashSet classes.
Professional help with C programming assignments offered by expert programmers who will provide you thoroughly commented code and ensure you submit top notch work.
An Introduction to Programming in Java: ArraysMartin Chapman
An Introduction to Programming in Java: Arrays. Last delivered in 2012. All educational material listed or linked to on these pages in relation to King's College London may be provided for reference only, and therefore does not necessarily reflect the current course content.
Homework Assignment – Array Technical DocumentWrite a technical .pdfaroraopticals15
Homework Assignment – Array Technical Document
Write a technical document that describes the structure and use of arrays. The document should
be 3 to 5 pages and include an Introduction section, giving a brief synopsis of the document and
arrays, a Body section, describing arrays and giving an annotated example of their use as a
programming construct, and a conclusion to revisit important information about arrays described
in the Body of the document. Some suggested material to include:
Declaring arrays of various types
Array pointers
Printing and processing arrays
Sorting and searching arrays
Multidimensional arrays
Indexing arrays of various dimension
Array representation in memory by data type
Passing arrays as arguments
If you find any useful images on the Internet, you can use them as long as you cite the source in
end notes.
Solution
Array is a collection of variables of the same type that are referenced by a common name.
Specific elements or variables in the array are accessed by means of index into the array.
If taking about C, In C all arrays consist of contiguous memory locations. The lowest address
corresponds to the first element in the array while the largest address corresponds to the last
element in the array.
C supports both single and multi-dimensional arrays.
1) Single Dimension Arrays:-
Syntax:- type var_name[size];
where type is the type of each element in the array, var_name is any valid identifier, and size is
the number of elements in the array which has to be a constant value.
*Array always use zero as index to first element.
The valid indices for array above are 0 .. 4, i.e. 0 .. number of elements - 1
For Example :- To load an array with values 0 .. 99
int x[100] ;
int i ;
for ( i = 0; i < 100; i++ )
x[i] = i ;
To determine to size of an array at run time the sizeof operator is used. This returns the size in
bytes of its argument. The name of the array is given as the operand
size_of_array = sizeof ( array_name ) ;
2) Initialisg array:-
Arrays can be initialised at time of declaration in the following manner.
type array[ size ] = { value list };
For Example :-
int i[5] = {1, 2, 3, 4, 5 } ;
i[0] = 1, i[1] = 2, etc.
The size specification in the declaration may be omitted which causes the compiler to count the
number of elements in the value list and allocate appropriate storage.
For Example :- int i[ ] = { 1, 2, 3, 4, 5 } ;
3) Multidimensional array:-
Multidimensional arrays of any dimension are possible in C but in practice only two or three
dimensional arrays are workable. The most common multidimensional array is a two
dimensional array for example the computer display, board games, a mathematical matrix etc.
Syntax :type name [ rows ] [ columns ] ;
For Example :- 2D array of dimension 2 X 3.
int d[ 2 ] [ 3 ] ;
A two dimensional array is actually an array of arrays, in the above case an array of two integer
arrays (the rows) each with three elements, and is stored row-wise in memory.
For Example :- Program to fill .
An array is a group of data items of same data type that share a common name. Ordinary variables are capable of holding only one value at a time. If we want to store more than one value at a time in a single variable, we use arrays.
An array is a collective name given to a group of similar variables. Each member in the group is referred to by its position in the group.
Arrays are alloted the memory in a strictly contiguous fashion. The simplest array is a one-dimensional array which is a list of variables of same data type. An array of one-dimensional arrays is called a two-dimensional array.
The objective of the Level 5 Diploma in Information Technology is to provide learners with an excellent foundation for a career in a range of organisations. It designed to ensure that each learner is ‘business ready’: a confident, independent thinker with a detailed knowledge of Information Technology, and equipped with the skills to adapt rapidly to change.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
3. Review
A Conditionally-Controlled Loop repeats…
as long as a particular condition exists.
A Count-Controlled Loop repeats…
a specific number of times.
A count-controlled loop has three elements
An initialization expression
A test expression
An update expression
The difference between the prefix and postfix
increment operators is…
pretest increments before the value of the operand is
evaluated, posttest increments after the value of the
operand is evaluated.
4. Review
A Sentinel Value is…
a special value that cannot be mistaken for normal input
that signals that a loop should terminate.
break in a loop…
makes the program’s control flow go to the statement
following the loop.
continue in a loop…
skips to the next iteration of the loop.
Java provides a class that generates pseudo-random
numbers called…
Random
5. Arrays
So far we have worked primarily with primitive
variables
One characteristic of primitive variables is that they hold
one value at a time.
int x = 100 – can only hold one integer value at a time
(100 at this time)
Imagine that you want to hold the names of 100
people at a time.
What would you have to do?
Declare 100 variables, one for each name.
Better solution: Use Arrays.
Arrays are complex variables that can hold multiple values of
the same data type.
Now we can declare a single array that holds all the names.
In Java, Arrays are objects and behave very similarly
(use new keyword to create the object, has methods,
etc.)
6. There are two types of array:
Single Dimensional Array (1D Array)
One-dimensional array(1-D): It is a single array that holds multiple
values of the same type.
Multidimensional Array (nth-D Array)
In such case, data is stored in row and column based index (matrix form).
Types of Arrays
7. One-Dimensional Array (1D)
To declare an integer array:
int[] numbers;
It is just like declaring any primitive variable, EXCEPT for the[]
between the data type and the identifier.
Just like any other object, this does not create the array, it
creates a reference variable that can point to an array.
To create an array object for this reference variable:
numbers = new int[6];
The number inside of the square brackets is called the array’s
size declarator.
An array’s Size Declarator indicates the number of elements, or
values the array can hold.
Individual values inside of an array are called elements.
So the numbers array can hold 6 integers.
You can declare and create on the same line like any other
object:
int[] numbers = new int [6];
8. The elements in an array are numbered starting
from 0.
So the first element has index 0.
The size declarator must be a non-negative
integer expression.
Often cases we know the size of the array when
writing the code and can just use a literal.
However, it is common practice to use a constant as the
size declarator.
final int NUM_ELEMENTS = 6;
double[] numbers = new double [NUM_ELEMENTS];
Once an array is created the size cannot change!
One-Dimensional Array (1D)
9. Accessing Array Elements
Even though, the array has one name, we can access
the individual elements by their index (or subscript).
An element’s Index (or Subscript) is a uniquely
identifying number that is used to pinpoint its position in
the array.
So, if I want a specific element, I use its index.
Again, indices start at 0.
When you access an element in the array, you can
use it just like any simple variable of the array’s
declared type.
The following statement assigns 20 to the first
element in the numbers array:
numbers[0] = 20;
To access an element of an array, simply use the
array name followed by the element’s index inside of
square brackets.
10. Array Example 1
New Topics:
Arrays
class ArrayExample {
public static void main(String[] args) {
int[] age = new int[5];
System.out.println(age[0]);
System.out.println(age[1]);
System.out.println(age[2]);
System.out.println(age[3]);
System.out.println(age[4]);
}
}
11. Array Example 2
This seems repetitive…
I have to use a separate segment of code for taking
in the employees hours and for printing the result
out.
Is there a better way?
Answer: Yes, using loops.
Arrays work great with loops, because you can
loop through the elements of the array and
perform operations on them.
12. Bounds Checking and Off-by-One
Errors
What is the problem with this?
int[] numbers = new int [3];
numbers[5] = 10;
Answer: The index 5 is out of the bounds defined by the size
declarator.
Java performs bounds checking at runtime.
In the case with Java that means that if you attempt to index an
element outside of the array’s bounds, it will throw an exception
(cause an error and terminate your program).
We will not discuss exceptions in this course.
What is the problem with this?
int[] numbers = new int [3];
numbers[3] = 10;
Answer: The index 3 is still out of the array’s bounds.
Because indexing starts at 0, the last element of the array is the
size of the array minus 1.
This is called an Off-by-One error.
13. Array Declaration Notes
You can initialize Arrays just like any other variables.
int[] numbers = {1, 2, 3, 4, 5};
This array has an implicit size of 5 and the values in the initialization are
indexed from left to right.
Example: ArrayInitialization.java
Java also allows for two different syntactical forms for declaring an
array:
int[] numbers;
int numbers[];
The difference is when you declare multiple arrays on the same
line:
int[] numbers1, numbers2, numbers3;
This declares three reference variables to integer arrays
int numbers1[], numbers2, numbers3;
This declares one reference variable to an integer array and two primitive
integer variables
int numbers1[], numbers2[], numbers3[];
This, again, declares three reference variables to integer arrays
14. Array Elements
Individual array elements can be treated like any simple
variable of that type.
int[] numbers = new int[5];
int x = 5;
numbers[1] = x + 5;
x = numbers[1] + 20;
numbers[2] = numbers[1] / 5;
numbers[2]++;
Also, since arrays are objects in Java, they have methods
and data members.
For instance the length data member holds the number of
elements in the array.
int size = numbers.length;
This is helpful for looping through an array.
15. Enhanced for Loop
The last kind of loop we will be discussing in this
course is called the enhanced for loop.
The Enhanced for Loop is a special loop that iterates
through the elements in a collection (in this case array)
and allows access to each element.
Each iteration of the loop corresponds to an element in
the array.
General Form:
for(dataType elementVariable : array)
block or statement
dataType – The type of the array
elementVariable – A variable that holds the value of
the current iteration’s element.
array – The array in which we are iterating through.
16. Enhanced for Loop Example
Enhanced for Loop
class EnhancedForLoop {
public static void main(String[] args)
{
int primes[] = { 2, 3, 5, 7, 11, 13,
17, 19, 23, 29};
for (int t: primes) {
System.out.println(t);
}
}
}
Output:
2
3
5
7
11
13
17
19
23
29
17. When NOT To Use the Enhanced
for Loop
The enhanced for loop is useful for when you
need only all the values of the array, but there are
many situations when you should NOT use it:
1. If you need to change the contents of an array
element
2. If you need to work through the array elements in
reverse order
3. If you need to access some of the array elements,
but not all of them
4. If you need to simultaneously work with two or
more arrays within the loop
5. If you need to refer to the index of a particular
element
If any of these cases apply, use a regular for
loop.
18. Allowing the User to Specify an
Array’s Size
Since the size declarator is an integer, you can let
the user enter an integer, and then create an
array of that size.
19. Reassigning Reference Variables
and Array Copying
As stated before, you cannot change the size of an
array once it has been set.
You can, however, make the reference variable point to
a new array.
int[] numbers = {1, 2, 3, 4, 5};
numbers = new int [10];
What is the problem with this?
Now numbers has no values in it!
What you need to do is copy the elements of the old
array to the new one, and make the original reference
variable point to the new array:
1. Create a new reference variable
2. Make the new reference variable point to an array of the
newly specified size
3. Use a loop to assign the elements from the old array to the
new one.
4. Assign the new reference variable to the old one.
20. Array Copying Example
Array Copying
public class ArrayCopying{
public static void main(String[] args) {
int a[] = {1, 8, 3};
// Create an array b[] of same size as a[]
int b[] = new int[a.length];
// Copy elements of a[] to b[]
for (int i=0; i<a.length; i++)
b[i] = a[i];
// Change b[] to verify that b[] is different
// from a[]
b[0]++;
System.out.println("Contents of a[] ");
for (int i=0; i<a.length; i++)
System.out.print(a[i] + " ");
System.out.println("nnContents of b[] ");
for (int i=0; i<b.length; i++)
System.out.print(b[i] + " ");
}
}
Output:
Contents of a[]
1 8 3
Contents of b[]
2 8 3
21. Two-Dimensional Array (2D)
Syntax to Declare 2D Array in Java :
dataType[ ][ ] arr ; (or)
dataType
dataType
dataType
[ ][ ]arr ; (or)
arr[ ][ ]; (or)
[ ]arr[ ];
Example to instantiate Multidimensional Array inJava:
int[ ][ ] arr=new int[3][3]; //3 row and 3 column
Example to initialize Multidimensional Array in Java:
arr[0][0]=1; arr[0][1]=2; arr[0][2]=3;
arr[1][0]=4; arr[1][1]=5; arr[1][2]=6;
arr[2][0]=7; arr[2][1]=8; arr[2][2]=9;
22. Example
class GFG {
public static void main(String[] args)
{
int[][] arr = { { 1, 2 }, { 3, 4 } };
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 2; j++) {
System.out.print(arr[i][j] + " ");
}
System.out.println();
}
}
}
Output:
1 2
3 4