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

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 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 BufferedWriter Java InputStreamReader Java File Java Read File Line By Line Java FileOutputStream Jar File in Java

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

Java Differences

Java vs JavaScript Python vs Java Kotlin vs Java Java vs C++ C# vs Java Static vs Non-static in Java C vs Java int vs Integer in Java Stack vs Heap in Java Java Array vs ArrayList

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 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 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 achieve abstraction in Java How to call static method in Java

Java 8 Features

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

Java 9 Features

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

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.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

All the important string methods in Java

What is a String?

Strings are a bundle of different characters that are normally used in Java programming language. 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 String:

The normal way of creating 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 of a creating String is:

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

Methods of String

Length():

The length of a string is the number of characters it holds. The length() function in Java calculates the number of characters in a String.

Example:

package codes;
import java.lang.String;
public class StringMethods {
public static void main(String[] args) {
String str = "Hello World";
System.out.println(str.length());
}
}

OUTPUT:

11

String to CharArray():

This technique is used to create a Character Array from all of the characters in a string. This is commonly used in string manipulation software.

Example:

public class StringMethods {
 
    public static void main(String[] args) {
         
        String str = "HELLO";
        char[] chars = str.toCharArray();
        System.out.println(chars);
        for (int i= 0; i< chars.length; i++) {
            System.out.println(chars[i]);
        }
    }
 
}

OUTPUT:

H
E
L
L
O

String charAt()

This method is used to extract a single character from a string of characters.

Syntax:

char charAt(int i);

The value of ‘i’ should not be negative and it should specify the location of a given String i.e. if a String length is 5, then the value of ‘i’ should be less than 5.

Example:

public class StringMethods {
 
public static void main(String[] args) {
String str = "HELLO WORLD";
        System.out.println(str.charAt(0));
        System.out.println(str.charAt(1));
        System.out.println(str.charAt(3));
        System.out.println(str.charAt(4));
        System.out.println(str.charAt(6));
  }
 }

OUTPUT:

H
L
O
W

equals (Object obj):

This method returns a Boolean value, indicating if the comparing string matches or not.

Example:

public class EqualsSample{ 
           public static void main(String args[]){ 
 
                   String s1="java"; 
                   String s2="java"; 
                   String s3="string"; 
 
                   System.out.println(s1.equals(s2));
                   System.out.println(s1.equals(s3)); 
            }
}

Output:

True
False

compareTo(String certainString):

This is a Comparable interface method that the String class implements. It is used to compare a string to the one currently in use string. As a consequence of the comparison, the method returns a value of 0 or a positive or negative number.

  • When both the strings are equal it returns 0.
  • If string 1st is less than string 2nd it returns negative.
  • If string 1st is greater than string 2nd it returns positive.

Example:

public class CompareToSample{ 
           public static void main(String args[]){ 
           String s1="string "; 
           String s2="string"; 
           String s3="ring"; 
           String s4="swing"; 
 
           System.out.println(s1.compareTo(s2));
           //0 because both are equal 
 
           System.out.println(s1.compareTo(s3));
           //1 because "s" is 1 time greater than "r"
 
           System.out.println(s1.compareTo(s4)); 
           // -3 because "t" is 3 times lower than "w"
           }
 }

Output:

0
1
-3

replace(char oldLetter, char newLetter) :

This method returns a new string in which the old character is replaced by the new character in all of the string's occurrences.

Example:

public class EqualsSample{ 
          public static void main(String args[]){ 
 
                   String s1="swap";
                   String s2 = replace(“w”,”n”); 

String contains():

This method is used to identify whether or not a substring belongs to the main String. The type of the return value is Boolean.

 

Example:

public class StringMethods {
public static void main(String[] args) {
String str = "helloworld";
        String str1 = "hello";
        String str2 = "java";
        System.out.println("hello is a part of helloworld: " 
str.contains(str1));
System.out.println("java is a part of helloworld: " + str.contains(str2));
    }
}

OUTPUT:

hello is a part of helloworld: true
java is a part of helloworld: false

Java String split()

A split() method divides or separates a supplied String into several substrings separated by delimiters ("", " ", etc.).

Example:

public class StringMethods {
public static void main(String[] args) {
String str = "MyxyznamexyzisxyzJohn”
String[] split = str.split("xyz");
for (String obj: split) {
System.out.println(obj);
        }
   }
}

 OUTPUT:

My
name
is
John

Java String indexOf():

This method is used to execute a search of the main String for a specified character or substring. Another often used approach is lastIndexOf().

To find the first occurrence of a character, use indexOf(). The lastIndexOf() function is used to find the character's last occurrence.

Example:

public class StringMethods {
 
    public static void main(String[] args) {
         
        String str = "Saket Saurav " + "performing a search";
        System.out.println(str);
        System.out.println("index of 'p' is " + str.indexOf('p'));
        System.out.println("index of 'u' is " + str.indexOf('u'));
        System.out.println("last index of 'S' is " + str.lastIndexOf('S'));
        System.out.println("last index of 's' is " + str.lastIndexOf('s'));
    }
 
}

OUTPUT:

Saket Saurav performing a search
index of ‘p’ is 13
index of ‘u’ is 8
last index of ‘S’ is 6
last index of ‘s’ is 26

String Reverse():

To reverse the input characters of a String, use the StringBuffer reverse() function.

Example:

public class StringMethods {
 
    public static void main(String[] args) {
         
        String str = "dlrowolleh";
        StringBuffer sb = new StringBuffer(str);
        sb.reverse();
        System.out.println(sb);
    }
}

OUTPUT:

Helloworld

Substring():

The Substring() method is normally used to give the substring of the main String by specifying the starting and the last index of that particular substring.

Example:

public class StringMethods {
 
    public static void main(String[] args) {
         
        String str = "tutorialsandexamples";
        System.out.println(str.substring(0,8));
//It will start from 8th character and extract the substring till 12th character
    }
}

OUTPUT:

tutorials



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