StringBuilder getChars() in Java with Examples
The getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin) method of StringBuilder class copies the characters starting at the given index:srcBegin to index:srcEnd-1 from String contained by StringBuilder into an array of char passed as parameter to function.
- The characters are copied from StringBuilder into the array dst[] starting at index:dstBegin and ending at index:dstbegin + (srcEnd-srcBegin) – 1.
- The first character to be copied from StringBuilder to array is at index srcBegin and the last character to be copied is at index srcEnd-1.
- The total number of characters to be copied is equal to srcEnd-srcBegin.
Syntax:
public void getChars(int srcBegin, int srcEnd,
char[] dst, int dstBegin)
Parameters: This method accepts four different parameters:
- srcBegin: represents index on which we have to start copying.
- srcEnd: represents index on which we have to stop copying.
- dst: represents the array to copy the data into.
- dstBegin: represents index of dest array we start pasting the copied data.
Return Value: This method does not return anything.
Exception: This method throws StringIndexOutOfBoundsException if:
- srcBegin < 0
- dstBegin < 0
- srcBegin > srcEnd
- srcEnd > this.length()
- dstBegin+srcEnd-srcBegin > dst.length
Below programs demonstrate the getChars() method of StringBuilder Class:
Example 1:
// Java program to demonstrate// the getChars() 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 = " + str.toString()); // create a char Array char[] array = new char[7]; // get char from index 0 to 7 // and store in array start index 0 str.getChars(0, 7, array, 0); // print char array after operation System.out.print("Char array contains : "); for (int i = 0; i < array.length; i++) { System.out.print(array[i] + " "); } }} |
Output:
String = WelcomeGeeks Char array contains : W e l c o m e
Example 2:
// Java program to demonstrate// the getChars() Method. import java.util.*; class GFG { public static void main(String[] args) { // create a StringBuilder object // with a String pass as parameter StringBuilder str = new StringBuilder("evil dead_01"); // print string System.out.println("String = " + str.toString()); // create a char Array char[] array = new char[10]; // initialize all character to _(underscore). Arrays.fill(array, '_'); // get char from index 5 to 9 // and store in array start index 3 str.getChars(5, 9, array, 3); // print char array after operation System.out.print("char array contains : "); for (int i = 0; i < array.length; i++) { System.out.print(array[i] + " "); } }} |
Output:
String = evil dead_01 char array contains : _ _ _ d e a d _ _ _
Example 3: To demonstrate StringIndexOutOfBoundException
// Java program to demonstrate// exception thrown by the getChars() Method. import java.util.*; class GFG { public static void main(String[] args) { // create a StringBuilder object // with a String pass as parameter StringBuilder str = new StringBuilder("evil dead_01"); // create a char Array char[] array = new char[10]; // initialize all character to _(underscore). Arrays.fill(array, '_'); try { // if start is greater then end str.getChars(5, 2, array, 0); } catch (Exception e) { System.out.println("Exception: " + e); } }} |
Output:
Exception: java.lang.StringIndexOutOfBoundsException: srcBegin > srcEnd
