Java Tutorial

Java Tutorial Java Features C++ vs Java Java History Java Hello World Java Development Kit Java Runtime Environment Java Virtual Machine Difference between JDK, JRE, and JVM Memory Areas in Java Java Operators Java Keywords Primitive Data Types Variables

Java Loops

Java Do While Loop Java While Loop Java For Loop Java Enhanced For Loop

Java Programs

Java Basic Programs Factorial Program in Java Fibonacci Series Program in Java Prime Number Program in Java Palindrome Number Program in Java Armstrong Number Program in Java Anagram Program in Java Pattern Programs in Java Calculator Program in Java Leap Year Program in Java Addition Program in Java Number Pattern Programs in Java Star Pattern Programs in Java Package Program in Java Pyramid Program in Java Sorting Program in Java String Palindrome Program in Java Even Odd Program in Java For Loop Program in Java If Else Program in Java Switch Case Program in Java GCD Program in Java LCM Program in Java Hello Program in Java Matrix Program in Java Menu Driven Program in Java Series Program in Java Client Server Program in Java Swapping Program in Java Pig Latin Program in Java Tower of Hanoi Program in Java Recursion Program in Java Matrix Multiplication Program in Java Perfect Number Program in Java Classes and Objects in Java Example Programs String Programs in Java Array Programs in Java Constructor Program in Java Inheritance Program in Java Abstract class Program in Java Interface Program in Java Encapsulation Program in Java Polymorphism Program in Java Exception Handling Program in Java Multithreading Program in Java Thread Program in Java Collection Programs in Java ArrayList Program in Java Stack Program in Java Applet Program in Java Swing Program in Java JDBC Program in Java How to run Java program in command prompt How to run Java program in Eclipse Program to find and replace characters on string in java Program to find the duplicate characters in a string Program to check whether a given character is present in a string or not Java Program to Print Permutations of String Java program to find frequency of characters in a string Java Program to remove duplicate characters in a string

Java Sorting

Sorting Algorithms in Java Merge Sort in Java Quick Sort in Java Bubble Sort in Java Insertion Sort in Java Selection Sort in Java Heap Sort in Java Radix Sort in Java Topological Sort in Java Bucket Sort in Java Counting Sort in Java

Java OOPs Concepts

OOPs - Object Oriented Programming Objects and Classes in Java Methods in Java Java Naming Conventions Constructors in Java Java this keyword Java static keyword Inheritance in Java Aggregation in Java Java super keyword Constructor Chaining and Constructor Overloading Java Polymorphism Static and Dynamic Binding in Java Java Abstraction Abstract class in Java Interface in Java Difference between Abstract class and Interface Java final keyword Packages in Java Access Modifiers in Java Java Wrapper classes Java Numbers Java Characters Java Integer Java Boolean Java Arrays Java Command Line Arguments Java strictfp Keyword Java Math

Java Strings

Java Strings Java String Methods StringBuilder in Java StringBuffer in Java Java Regular Expressions StringBuffer vs StringBuilder String vs StringBuffer String vs StringBuilder String Manipulation in Java Java String Concatenation How to Reverse a String in Java String Array in Java How to Compare Two Strings in Java How to Concatenate Two Strings in Java Why String in Immutable in Java Java.lang.NumberFormatException for Input String String Pool in Java Java Generate Random String How to take String Input in Java Java String Interview Questions

Java Exceptions

Exception Handling in Java Java try catch Java throw Java throws Difference between throw and throws Java finally Java Custom Exception Java Exception Propagation

Garbage Collection

Automatic Resource Management in Java Java Garbage Collection Java finalize() Java gc() Difference between final, finally and finalize

Multithreading

Multithreading in Java Process and Thread in Java Basic Terms in Multithreading Java Thread creation Thread Scheduler in Java Java Thread class DeadLock in Java

Java IO

Java IO Java Read File Java file Reader Java Buffer Reader Java file Writer Java BufferedWriter Java InputStreamReader Scanner in Java Java StringReader Java StringReader Class Java PrintWriter Java File Java Read File Line By Line Java FileInputStream Java FileOutputStream Java Create File Java Delete File Java Open File Java Read File to String Java copy file Java Read JSON file Jar File in Java Java FileNotFoundException

Serialization

Java Serialization Java transient

Networking

Java Network Programming Java Socket Programming Java URL Java URLConnection HttpURLConnection in Java Java InetAddress Java DatagramSocket and Java DatagramPacket

AWT

Java AWT

Swing

Swing in Java

Java Collections

Collections in Java Java List Interface ArrayList in Java LinkedList in Java Vector in Java Stack in Java ArrayList vs LinkedList in Java ArrayList vs Vector in Java Java Set Interface HashSet in Java LinkedHashSet in Java TreeSet in Java Java Queue Interface PriorityQueue in Java ArrayDeque in Java Java Map Interface HashMap in Java LinkedHashMap in Java TreeMap in Java Dictionary in Java Hashtable in Java Properties in Java Collections class in Java Java Comparable Java Comparator Comparable vs Comparator in Java

Java Generics

Generics in Java

Java Annotations

Annotations in Java

Java JDBC

Java JDBC Tutorial JDBC Architecture Types of JDBC Drivers JDBC vs ODBC Java Database Connectivity with MySQL Statements in java Prepared statement in Java Resultset in java Java ResultSetMetaData DatabaseMetaData in Java Callable Statement in Java Transaction Management in java Design of JDBC

Java Differences

Java vs JavaScript Python vs Java Kotlin vs Java Java vs C++ C# vs Java Java float vs double Java vs Scala Static vs Non-static in Java C vs Java int vs Integer in Java Java protected vs private Java vs Dot Net Stack vs Heap in Java Java Array vs ArrayList Java SE vs EE Difference between = = and equals ( ) in java Difference between C, C++, java

How to

How to run Java program How to set path in Java How to check the Java version in cmd How to install Java in Windows 10 How to run Java program in cmd How to add double quotes in a string in Java How to convert list to String in Java How to call a method in Java How to sort an array in Java How to iterate HashMap in Java How to write Java program How to create an array in Java How to create a package in Java How to generate random numbers in Java How to input String in Java How to create thread in Java How to find length of String in Java How to sort a string in Java How to use scanner in Java How to achieve multiple inheritance in Java How to find the length of an Array in Java How to run Java program in Eclipse How to call a function in Java How to create array of objects in Java How to create custom exception in Java How to import packages in Java How to run applet Program in Java How to take Array Input in Java How to achieve abstraction in Java How to call static method in Java How to compare characters in Java How to compare dates in Java How to create a linked list in Java How to get ASCII value of char in Java How to initialize string array in Java How to Install Java on MAC How to run java program in ubuntu How to find characters with the maximum number of times in a string java How to Set Java_home in Linux How to Split the String in Java with Delimiter How to uninstall the Java in Ubuntu How to Split String by Comma in Java How to remove special characters from String in Java How to remove last character from String in Java

Java 8 Features

Java 8 Features Lambda Expressions in Java Functional Interface in Java Streams in Java Java Base64 Encoding and Decoding Java Stringjoiner Class Parallel Arrays Sort in Java

Java 9 Features

Java 9 Tutorial Java 9 Try With Resources Java 9 Interface Private Method

Java 16

Java 16

Java 17

What is new in Java 17

Java Servlet Tutorial

Java Servlets Tutorial

Java JSP Tutorial

Java JSP Tutorial

Hibernate Tutorial

Hibernate Tutorial

Spring Tutorial

Spring Tutorial

Spring MVC Tutorial

Spring MVC Tutorial

Jenkins Tutorial

Jenkins Tutorial

Java Math Methods

Math.abs() Math.acos() Math.addExact() Math.asin() Math.atan () Math.atan2() Math.cbrt() Math.ceil() Math.copysign() Math.cos() Math.cosh() Math.decrementExact() Math.exp() Math.expm1() Math.floor() Math.floorDiv() Math.floorMod() Math.fma() Math.getExponent() Math.hypot() Math.IEEEremainder() Math.incrementExact() Math.log() Math.log10() Math.log1p() Math.max() Math.min() Math.multiplyExact() Math.multiplyFull() Math.negateExact() Math.nextAfter() Math.nextDown() Math.nextUp() Math.pow() Math.random() Math.rint() Math.round() Math.scalb() Math.signum() Math.sin() Math.sinh() Math.sqrt() Math.subtractExact() Math.tan() Math.tanh() Math.toDegrees() Math.toIntExact() Math.toRadians() Math.ulp()

Java String Methods

toCharArray() copyValueOf() endsWith() equals() equalsIgnoreCase() format() getBytes() getChars() hashCode() indexOf() intern() isEmpty() join() lastIndexOf() length() replace() replaceAll() replaceFirst() split() startsWith() subSequence() substring() toLowerCase() toUpperCase() trim() valueOf()

Java Conversion

Java Convert String to int Java Convert int to String Java Convert String to long Java Convert long to String Java Convert String to float Java Convert float to String Java Convert String to double Java Convert double to String Java Convert String to Date Java Convert Date to String Java Convert String to Object Java Convert Object to String Java Convert String to char Java Convert char to String Java Convert int to long Java Convert long to int

Misc

Functional Interfaces in Java Singleton class in Java Awesome explanation of Strings in Java Object class in Java Static class in Java All the important string methods in Java String Handling Method in Java What are Array strings in Java Advantages and Disadvantages of Strings in Java Big Decimal class in Java Class definition in Java Char and String differences in Java Difference between String, StringBuffer and StringBuilder in java Replace character in string Java String Coding Interview Questions in Java What is String in Java? String isnullorempty in Java String Matches in Java Trim Method in String Java Bean class in Java Libraries in Java Arithmetic Operations on String in Java Convert Char array to string in java Check whether Java is installed or not How to calculate time difference in Java How to stop execution after a certain time in Java Jagged Array in Java Java ArraylistRemove() Time Complexity Java Swing Time Picker Zigzag Array in Java Array and String based questions in Java Array and String with Examples in Java Best Practices to use String Class in Java What is string in Java why it's immutable Java String Java String Inbuilt functions Java String Matches vs Contains Sum of digits in string in java Check the presence of Substring in a String in java Java import packages Interfaces and Classes in Strings in Java Maximum length of string in java Hidden classes in Java Class memory in Java public static void main string args meaning in java Reverse a String in Java String Concatenation in Java Difference between String and Char Array in Java Buffer reader to read string in Java Split String into String Array in Java Reverse a String using Collections in Java Upcasting and Downcasting in Java String Declaration in Java Method Overloading In Java Java Solid Principles Java Architecture Binary Search Java Star Program in Java Java Type Casting Java Pass-by-Reference Java Framework List Java Destructors Java Control Statements Java Byte Code Java Beans Java Identifiers Character Array in Java Java Applications Java Substring Java Session Non-primitive data types in Java Matrix Multiplication in Java JIT in Java Java Tokens Java Externalization Default Virtual Behaviour in C++ vs Java Why we use static in Java Session Tracking in Java Knapsack problem in Java Java Logo Java exception list Java Iterator Java instance variable Frugal number in Java Fork Join in Java Date time API in java Compile time vs Runtime in java Compare time in java AES 256 Encryption in Java Advanced Java skills What is advance Java? User Defined Exception in Java Upcasting in Java Tree Implementation in Java Special Operators in Java Reentrant Lock in Java Perfect Number in Java Java logger Java LinkedList vs ArrayList File Operation in Java Differences between Byte Code and Machine Code Difference between String Tokenizer and split Method in Java Difference between JIT and JVM in Java Constructor Overloading in Java Conditional operator in Java Concurrent Linked Deque in Java with Examples Command Class in Java Java Break Keyword Best Java IDE Association in Java Access specifiers in Java

Char and String differences in Java

Characters in Java

Character (char) belongs to the characters group, which represents symbols in a character set, such as alphabets and numerals.

A Java char has 16 bits in length and has a range of 0 to 65,536. In addition, the normal ASCII character set spans 0 to 127.

Syntax of char Java.

char variable_name = ‘variable_value’;

Characteristics of Char in Java

As previously stated, the range is between 0 to 65,536.

Because Java uses the Unicode system rather than the ASCII coding system, the default size is 2 bytes.

The default value is 'u0000,' which is the lowest Unicode range.

Simple program to display the characters

public class example {
 
    public static void main(String[] args) {
         
        char c1 = 'a';
        char c2 = 'A';
         
        System.out.println("c1 is: " +c1);
        System.out.println("c2 is: " +c2);
         
    }
 }

OUTPUT:

c1 is: a
c2 is: A

Character using ASCII value

We've used integers to initialize three char Java variables in the example below. Those integers will be transformed into their ASCII equivalents when printed. The compiler will convert a number to a character and display the associated ASCII value.

Example:

public class example {
 
    public static void main(String[] args) {
         
        char c1, c2, c3;
         
        /*
         *  Since 69 and 71 are the ASCII value for E and G, 
         *  we have assigned c1 as 69 and c3 as 71.
         */
         
        c1 = 69;
        c2 = 'F';
        c3 = 71;
         
        System.out.println("The characters are: " + c1 + c2 + c3);
         
    }
 
}

OUTPUT:

The characters are: EFG

Breaking string into character Java

We'll split a String in the form of Character Java in this part. To begin, we've turned an input String into a Java character array. The function toString() method was then used to print the value of the original String as well as the characters contained within that array.

Example:

import java.util.Arrays;
 
public class example {
 
    public static void main(String[] args) {
         
        String str1 = "helloworld";
         
        // conversion into character array
        char[] chars = str1.toCharArray();
         
        System.out.println("Original String was: " + str1);
        System.out.println("Characters are: " + Arrays.toString(chars));
         
    }
 
}

OUTPUT:

Original string was: helloworld
Characters are: [h, e, l, l, o, w, o, r, l, d]

Incrementing and Decrementing the characters

We've initialized a Java character variable in the program below and then tried incrementing and decrementing it with the operator. Before and after each operation, a print statement is inserted to examine how the value changes.

Example:

public class example {
public static void main(String[] args) {
char c1 = 'C';
System.out.println("The value of c1 is: " + c1);
c1++;
System.out.println("After incrementing: " + c1);
c1--;
System.out.println("After decrementing: " + c1);
         }
}

OUTPUT:

The value of c1 is: C
After incrementing: D
After decrementing: C

Typecast integer to character Java

In this part, we've explicitly typecast an integer value to Java char after initializing a variable with an integer value. All of these numeric-initialized integer variables are associated with a certain character.

Example:

public class example {
 
    public static void main(String[] args) {
         
        int number1 = 75;
        char chars1 = (char)number1;
         
        int number2 = 73;
        char chars2 = (char)number2;
     
        int number3 = 84;
        char chars3 = (char)number3;
         
        int number4 = 69;
        char chars4 = (char)number4;
     
        System.out.println(chars1);
        System.out.println(chars2);
        System.out.println(chars3);
        System.out.println(chars4);
         
    }
 
}

OUTPUT:

K
I
T
E

Represent character into Unicode:

In this part, we've set the Unicode value for three Java characters (escape sequence). Following that, we simply printed those variables. The rest will be handled by the compiler, which will explicitly translate the Unicode value to a Java character.

Example:

public class example {
 
    public static void main(String[] args) {
         
        char chars1 = '\u0058';
        char chars2 = '\u0059';
        char chars3 = '\u005A';
         
        System.out.println("chars1, chars2 and chars3 are: " + chars1 + chars2 + chars3);
         
    }
 
}

OUTPUT:

chars1, chars2, and chars3 are: XYZ

Strings in Java?

Strings are a collection of characters that are commonly used in Java programming. Strings are regarded as objects in the Java programming language.

“String” is a Java platform class that allows you to construct and handle strings.

Creating Strings

The normal way to create a string in Java is to simply write:-

String s = “Hello World”;

The compiler constructs a String object with the value "Hello world!" whenever it detects a string phrase in your code.

String objects cannot be made by using the new keyword and a function Object, just like any other object. The String class provides 11 constructors that allow you to set the string's initial value from a variety of sources, including an array of characters.

Another way to create a string is :-

String s = new String (“Hello World”);

String Builder:

The char value, which is a one-character string, is represented by a String class object. We can't use an ASCII value in this case.

Syntax:

StringBuilder str = new StringBuilder();
str.append("GFG");

String Buffer:-

StringBuffer is a String companion class that provides a lot of the same functionality as strings. StringBuffer shows growable and writable character sequences, whereas string represents fixed-length, immutable character sequences.

Syntax:

StringBuffer s = new StringBuffer("Hello World");

String Tokenizer:-

The StringTokenizer class in Java is used to tokenize a string.

String Joiner:-

String Joiner is a java.util package class that is used to build a sequence of characters divided by a delimiter and optionally starting with a transferred prefix and finishing with a transferred suffix.

Syntax:

public StringJoiner(CharSequence delimiter);

As we study in the above part, we have sufficient knowledge about replacing a character in a string

So, there are three ways to replace character in a string:

String Builder:

In contrast to the String Class, the StringBuilder class includes a built-in function for this — setCharAt (). By calling this function and giving the character and the index as parameters, you can replace the character at a given index.

Difference between char and strings

StringsCharacters  
A string is a collection of characters that are represented as a single data type.A Character Array is a collection of char data in sequential order.
Strings supports build in functions like charAt(), substring() etc.Characters do not support build-in functions
Strings are unchangeable.Characters are changeable
Strings can be stored in memory in a variety of waysCharacter Array elements are sequentially stored at increasing memory regions.
The String Constant Pool holds all of the StringsThe Heap holds all of the Character Arrays.
In Java, it is not recommended to store passwords.In Java, this is the preferred method for saving passwords.



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