Java String substring()

The Java substring() method extracts a part of the string (substring) and returns it.

Example

class Main {
  public static void main(String[] args) {
    String str1 = "java is fun";

    // extract substring from index 0 to 3
System.out.println(str1.substring(0, 4));
} } // Output: java

substring() Syntax

string.substring(int startIndex, int endIndex)

substring() Parameters

The substring() method can take a maximum of two arguments.

  • startIndex - the beginning index
  • endIndex (optional) - the ending index

substring() Return Value

The substring() method returns a substring from the given string.

  • The substring begins with the character at the startIndex and extends to the character at index endIndex - 1
  • If the endIndex is not passed, the substring begins with the character at the specified index and extends to the end of the string
Working of Java String substring() method
Working of Java String substring() method

Note: You will get an error if

  • startIndex/endIndex is negative or greater than string's length
  • startIndex is greater than endIndex

Example 1: Java substring() With Only Start Index

class Main {
  public static void main(String[] args) {
    String str1 = "program";

    //  1st character to the last character
System.out.println(str1.substring(0)); // program
// 4th character to the last character System.out.println(str1.substring(3)); // gram } }

Example 2: Java substring() With Start and End Index

class Main {
  public static void main(String[] args) {
    String str1 = "program";

    // 1st to the 7th  character
    System.out.println(str1.substring(0, 7));  // program

    // 1st to the 5th  character
System.out.println(str1.substring(0, 5)); // progr
// 4th to the 5th character System.out.println(str1.substring(3, 5)); // gr } }

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