This document provides an overview of strings in Java. It discusses that a string is a sequence of characters that can be treated as an object with various methods. Some key points include:
- Strings are immutable objects that provide methods for length, character access, concatenation, substring extraction, conversion, matching/replacing patterns, and finding substrings.
- The String class has over 40 methods for manipulating strings including comparing, converting, replacing, and splitting strings.
- Regular expressions can be used with methods like matches, replaceAll, replaceFirst and split to perform powerful pattern matching on strings.
CSE 220 Assignment 3 Hints and Tips Some hints for approa.docxfaithxdunce63732
CSE 220 Assignment 3 Hints and Tips
Some hints for approaching this assignment is as follows:
Approaching the assignment :
General Overview
It would be a good thing if before you start your assignment you try to decompose the problem
you are trying to solve into small segments. Each segment can be then written and tested for
any bugs or errors. Doing so will help you learn the true nature of functions and how effective
they can be.
The assignment requires that you read a string from either the stdin or a file and then count the
frequency of words in it and display it to stdout or to a file. We can look at this in the following
way :
1) Read an input from one of two sources
a. stdin
b. an input file
2) Find the frequency of words from input string
3) Write the words and their frequency to one of two ouputs
a. Stdout
b. An outputifle
One way of solving the problem
One way of approaching this code would be to create a structure which will hold a word and its
frequency and then create an array of that structure to accommodate all the unique words in
the input. So you would create a structure as follows:
struct wordStorage
{
char word[50];
int count;
};
Then when you want to create an array of that structure you would write it out as :
struct wordStorage arr[size];
So we created an array to of size number of elements of the structure wordStorage created
above.
This array can then be used to keep track of all the unique words you come across in the input
string and their frequencies. You can create arrays of this structure after you have defined the
structure itself.
You could then use the following prototypes in your code:
1. void decomposeToArray(char *para,char wordarr[1000][50])
This function takes in a string para and stores all the words in that string. You can
modify it to return the array of words containing all the words using –
char** decomposeToArray(char *para,char wordarr[1000][50]);
2. void frequencyOfWords(struct wordStorage *wordarr,char wordList[1000][50])
This function takes in a structure array in which element contains a word and its
frequency and the array of words that you created using decomposeToArray(args).
Instead of using a void function you can modify it so that it stores the words and
their frequency as an array of the given structure and then returns the structure
array. The prototype then becomes –
struct wordStorage* frequencyOfWords(wordList[1000][50])
3. void readFromFile(char *filename,char sentence[1000])
This function takes in the name of a file and a string to store all the contents of the
file. You can use pass by reference to keep track of the string that is storing the
string OR you could modify the function to read the name of a file and return a
string using:
char* readFromFile(char *filename)
4. void writeToFile(char *filename,struct wordStorage *wordarr);
This function prints the contents of the struct.
CSE 220 Assignment 3 Hints and Tips Some hints for approa.docxfaithxdunce63732
CSE 220 Assignment 3 Hints and Tips
Some hints for approaching this assignment is as follows:
Approaching the assignment :
General Overview
It would be a good thing if before you start your assignment you try to decompose the problem
you are trying to solve into small segments. Each segment can be then written and tested for
any bugs or errors. Doing so will help you learn the true nature of functions and how effective
they can be.
The assignment requires that you read a string from either the stdin or a file and then count the
frequency of words in it and display it to stdout or to a file. We can look at this in the following
way :
1) Read an input from one of two sources
a. stdin
b. an input file
2) Find the frequency of words from input string
3) Write the words and their frequency to one of two ouputs
a. Stdout
b. An outputifle
One way of solving the problem
One way of approaching this code would be to create a structure which will hold a word and its
frequency and then create an array of that structure to accommodate all the unique words in
the input. So you would create a structure as follows:
struct wordStorage
{
char word[50];
int count;
};
Then when you want to create an array of that structure you would write it out as :
struct wordStorage arr[size];
So we created an array to of size number of elements of the structure wordStorage created
above.
This array can then be used to keep track of all the unique words you come across in the input
string and their frequencies. You can create arrays of this structure after you have defined the
structure itself.
You could then use the following prototypes in your code:
1. void decomposeToArray(char *para,char wordarr[1000][50])
This function takes in a string para and stores all the words in that string. You can
modify it to return the array of words containing all the words using –
char** decomposeToArray(char *para,char wordarr[1000][50]);
2. void frequencyOfWords(struct wordStorage *wordarr,char wordList[1000][50])
This function takes in a structure array in which element contains a word and its
frequency and the array of words that you created using decomposeToArray(args).
Instead of using a void function you can modify it so that it stores the words and
their frequency as an array of the given structure and then returns the structure
array. The prototype then becomes –
struct wordStorage* frequencyOfWords(wordList[1000][50])
3. void readFromFile(char *filename,char sentence[1000])
This function takes in the name of a file and a string to store all the contents of the
file. You can use pass by reference to keep track of the string that is storing the
string OR you could modify the function to read the name of a file and return a
string using:
char* readFromFile(char *filename)
4. void writeToFile(char *filename,struct wordStorage *wordarr);
This function prints the contents of the struct.
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.
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.
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.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
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.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)
String.pptx
1. BCSE103E
Module 2: String
Dr. S Ranjithkumar
Assistant Professor Senior Grade 1
School of Computer Science and Engineering,
Vellore Institute of Technology,
Vellore – 632014
Phone No: +91 9944401999
Mail ID: ranjithkumar.s@vit.ac.in
Location: PRP Block – 315 AB21
2. Introduction
• Suppose you need to write a program that replaces all occurrences of
a word in a file with a new word.
• How do you accomplish this?
• This chapter introduces strings and text files, which will enable you to
solve problems of this type
3. The String Class
• A string is a sequence of characters.
• In many languages, strings are treated as an array of characters, but in
Java a string is an object.
• The String class has 11 constructors and more than 40 methods for
manipulating strings.
• Not only is it very useful in programming, but also it is a good
example for learning classes and objects.
4. Constructing a String
• You can create a string object from a string literal or from an array of
characters.
• To create a string from a string literal, use a syntax like this one:
• String newString = new String(stringLiteral);
• The argument stringLiteral is a sequence of characters enclosed inside double
quotes.
• The following statement creates a String object message for the string literal
"Welcome to Java":
• String message = new String("Welcome to Java");
• Java treats a string literal as a String object.
• So, the following statement is valid:
• String message = "Welcome to Java";
5. • You can also create a string from an array of characters.
• For example, the following statements create the string “Good Day”:
• char[] charArray = {'G', 'o', 'o', 'd', ' ', 'D', 'a', 'y’};
• String message = new String(charArray);
6. Immutable Strings and Interned Strings
• A String object is immutable; its contents cannot be changed. Does
the following code change the contents of the string?
• String s = "Java";
• s = "HTML";
7. • Since strings are immutable and are ubiquitous in programming, the
JVM uses a unique instance for string literals with the same character
sequence in order to improve efficiency and save memory. Such an
instance is called interned. For example, the following statements:
• String s1 = "Welcome to Java";
• String s2 = new String("Welcome to Java");
• String s3 = "Welcome to Java";
• System.out.println("s1 == s2 is " + (s1 == s2));
• System.out.println("s1 == s3 is " + (s1 == s3));
• Output
• s1 == s2 is false
• s1 == s3 is true
9. • How do you compare the contents of two strings? You might attempt to
use the == operator, as follows:
if (string1 == string2)
System.out.println("string1 and string2 are the same object");
else
System.out.println("string1 and string2 are different objects");
• The code given below, for instance, can be used to compare two strings:
if (string1.equals(string2))
System.out.println("string1 and string2 have the same contents");
else
System.out.println("string1 and string2 are not equal");
10. • For example, the following statements display true and then false.
String s1 = new String("Welcome to Java");
String s2 = "Welcome to Java";
String s3 = "Welcome to C++";
System.out.println(s1.equals(s2)); // true System.out.println(s1.equals(s3)); //
false
• The compareTo method can also be used to compare two strings.
• For example, consider the following code:
s1.compareTo(s2)
11. String Length, Characters, and Combining
Strings
• The String class provides the methods for obtaining length, retrieving
individual characters, and concatenating strings
• You can get the length of a string by invoking its length() method.
• For example, message.length() returns the length of the string
message.
12. • The s.charAt(index) method can be used to retrieve a specific character
in a string s, where the index is between 0 and s.length()–1.
• For example, message.charAt(0) returns the character W,
13. Concatenate
• You can use the concat method to concatenate two strings. The
statement shown below,
• for example, concatenates strings s1 and s2 into s3:
String s3 = s1.concat(s2);
• Since string concatenation is heavily used in programming, Java
provides a convenient way to accomplish it.
• You can use the plus (+) sign to concatenate two or more strings. So
the above statement is equivalent to String s3 = s1 + s2;
• The following code combines the strings message, " and ", and "HTML"
into one string:
String myString = message + " and " + "HTML";
14. Obtaining Substrings
• You can obtain a single character from a string using the charAt
method.
• You can also obtain a substring from a string using the substring
method in the String class
15. • For example,
String message = "Welcome to Java".substring(0, 11) + "HTML";
• The string message now becomes "Welcome to HTML".
16. Converting, Replacing, and Splitting Strings
• The String class provides the methods for converting, replacing, and
splitting strings, as shown
17. • For example,
• "Welcome". returns a new string, welcome.
• "Welcome". returns a new string, WELCOME.
• " Welcome ". returns a new string, Welcome.
• "Welcome". returns a new string, WAlcomA.
• "Welcome". returns a new string, WABlcome.
• "Welcome". returns a new string, WABlcomAB.
• "Welcome". returns a new string, WABcome.
• The split method can be used to extract tokens from a string with the
specified delimiters.
• For example, the following code
String[] tokens = "Java#HTML#Perl".split("#", 0);
for (int i = 0; i < tokens.length; i++)
System.out.print(tokens[i] + " ");
18. Matching, Replacing and Splitting by Patterns
• You can match, replace, or split a string by specifying a pattern. This is
an extremely useful and powerful feature, commonly known as
regular expression.
• Regular expressions seem complex to beginning students. For this
reason, two simple patterns are used in this section.
• Please refer to Supplement III.H, “Regular Expressions,” for further
studies.
19. • Let us begin with the matches method in the String class. At first glance,
the matches method is very similar to the equals method. For example,
the following two statements both evaluate to true.
"Java".matches("Java");
"Java".equals("Java");
• However, the matches method is more powerful. It can match not only a
fixed string, but also a set of strings that follow a pattern.
• For example, the following statements all evaluate to true:
"Java is fun".matches( )
"Java is cool".matches( )
"Java is powerful".matches( ) "Java.*“
in the preceding statements is a regular expression.
It describes a string pattern that begins with Java followed by any zero or more
characters. Here, the substring matches any zero or more characters.
20. • The replaceAll, replaceFirst, and split methods can be used with a regular
expression.
• For example, the following statement returns a new string that replaces
$, +, or # in "a+b$#c" with the string NNN.
String s = "a+b$#c".replaceAll("[$+#]", "NNN");
System.out.println(s);
21. • Here the regular expression [$+#] specifies a pattern that matches $, +, or
#. So, the output is aNNNbNNNNNNc.
• The following statement splits the string into an array of strings delimited
by punctuation marks.
String[] tokens = "Java,C?C#,C++".split("[.,:;?]");
for (int i = 0; i < tokens.length; i++)
System.out.println(tokens[i]);
• Here the regular expression [.,:;?] specifies a pattern that matches ., ,, :, ;,
or ?.
• Each of these characters is a delimiter for splitting the string. So, the string
is split into Java, C, C#, and C++, which are stored into array tokens.
22. Finding a Character or a Substring in a String
• The String class provides several overloaded indexOf and lastIndexOf
methods to find a character or a substring in a string,
• For example,
"Welcome to Java".indexOf('W') returns 0.
"Welcome to Java".indexOf('o') returns 4.
"Welcome to Java".indexOf('o', 5) returns 9.
"Welcome to Java".indexOf("come") returns 3.
"Welcome to Java".indexOf("Java", 5) returns 11.
"Welcome to Java".indexOf("java", 5) returns -1.
"Welcome to Java".lastIndexOf('W') returns 0.
"Welcome to Java".lastIndexOf('o') returns 9.
"Welcome to Java".lastIndexOf('o', 5) returns 4.
"Welcome to Java".lastIndexOf("come") returns 3.
"Welcome to Java".lastIndexOf("Java", 5) returns -1.
"Welcome to Java".lastIndexOf("Java") returns 11.
24. • Problem: Counting Each Letter in a String The problem is to write a
program that prompts the user to enter a string and counts the
number of occurrences of each letter in the string regardless of case.
Here are the steps to solve this problem:
• 1. Convert all the uppercase letters in the string to lowercase using
the toLowerCase method in the String class.
• 2. Create an array, say counts of 26 int values, each of which counts
the occurrences of a letter. That is, counts[0] counts the number of
a’s, counts[1] counts the number of b’s, and so on.
• 3. For each character in the string, check whether it is a (lowercase)
letter. If so, increment the corresponding count in the array
Editor's Notes
Often you encounter problems that involve string processing and file input and output. Suppose you need to write a program that replaces all occurrences of a word in a file with a new word. How do you accomplish this? This chapter introduces strings and text files, which will enable you to solve problems of this type
A string is a sequence of characters. In many languages, strings are treated as an array of characters, but in Java a string is an object. The String class has 11 constructors and more than 40 methods for manipulating strings. Not only is it very useful in programming, but also it is a good example for learning classes and objects.
The answer is no. The first statement creates a String object with the content “Java” and assigns its reference to s. The second statement creates a new String object with the content “HTML” and assigns its reference to s. The first String object still exists after the assignment, but it can no longer be accessed, because variable s now points to the new object as shown in Figure
In the preceding statements, s1 and s3 refer to the same interned string “Welcome to Java”, therefore s1 == s3 is true.
However, s1 == s2 is false, because s1 and s2 are two different string objects, even though they have the same contents.
However, the == operator checks only whether string1 and string2 refer to the same object;
it does not tell you whether they have the same contents.
Therefore, you cannot use the == operator to find out whether two string variables have the same contents.
Instead, you should use the equals method.
The method returns the value 0 if s1 is equal to s2, a value less than 0 if s1 is lexicographically (i.e., in terms of Unicode ordering) less than s2, and a value greater than 0 if s1 is lexicographically greater than s2.
The actual value returned from the compareTo method depends on the offset of the first two distinct characters in s1 and s2 from left to right.
For example, suppose s1 is "abc" and s2 is "abg", and s1.compareTo(s2) returns -4.
The first two characters (a vs. a) from s1 and s2 are compared. Because they are equal, the second two characters (b vs. b) are compared.
Because they are also equal, the third two characters (c vs. g) are compared. Since the character c is 4 less than g, the comparison returns -4.
Once a string is created, its contents cannot be changed.
The methods toLowerCase, toUpperCase, trim, replace, replaceFirst, and replaceAll return a new string derived from the original string (without changing the original string!).
The toLowerCase and toUpperCase methods return a new string by converting all the characters in the string to lowercase or uppercase.
The trim method returns a new string by eliminating blank characters from both ends of the string.
Several versions of the replace methods are provided to replace a character or a substring in the string with a new character or a new substring.
