The subSequence(int start, int end) method of StringBuilder class is the inbuilt method used to return a subsequence of characters lie between index start and end-1 of this sequence. The subsequence starts with the char value at the index start and ends with the char value at (end-1). The length of the returned subsequence is end-start. So if start is equal to end then an empty subsequence is returned.
Syntax:
public CharSequence subSequence(int start, int end)
Parameters:
This method accepts two parameters:
- start which is Integer type value refers to the start index of subsequence.
- end which is Integer type value refers to the last index of subsequence.
Returns:
This method returns the specified subsequence in range start to end-1.
Exception:
if start or end are negative, if end is greater than length(), or if start is greater than end then IndexOutOfBoundsException is thrown.
Below programs illustrate the java.lang.StringBuilder.subSequence() method:
Example 1:
Java
// Java program to demonstrate// the subSequence() Method.class GFG { public static void main(String[] args) { // create a StringBuilder object // with a String pass as parameter StringBuilder str = new StringBuilder("WelcomeGeeks"); // print string System.out.println("String contains = " + str); // get subSequence between index 0 to 7 // using subSequence() and print System.out.println("SubSequence = " + str.subSequence(0, 7)); }} |
Output:
String length = 12 and contains = WelcomeGeeks SubSequence = Welcome
Example 2:
Java
// Java program to demonstrate// the subSequence() Method.class GFG { public static void main(String[] args) { // create a StringBuilder object // with a String pass as parameter StringBuilder str = new StringBuilder("Indian Team Played Well"); // print string System.out.println("String contains = " + str); // get subSequence between index 0 to 7 // using subSequence() and print System.out.println("SubSequence = " + str.subSequence(7, 18)); }} |
Output:
String contains = Indian Team Played Well SubSequence = Team Played
Example 3: When start > end:
Java
// Java program to demonstrate// Exception thrown by the subSequence() Method.class GFG { public static void main(String[] args) { // create a StringBuilder object // with a String pass as parameter StringBuilder str = new StringBuilder("Indian Team Played Well"); try { // get subSequence between index 0 to 7 // using subSequence() and print System.out.println(str.subSequence(19, 18)); } catch (Exception e) { e.printStackTrace(); } }} |
Output:
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
at java.lang.AbstractStringBuilder.substring(AbstractStringBuilder.java:935)
at java.lang.StringBuilder.substring(StringBuilder.java:76)
at java.lang.AbstractStringBuilder.subSequence(AbstractStringBuilder.java:912)
at java.lang.StringBuilder.subSequence(StringBuilder.java:76)
at GFG.main(File.java:16)
References:
https://docs.oracle.com/javase/10/docs/api/java/lang/StringBuilder.html#subSequence(int, int)
