How to swap String characters in Java?

Question

How can I swap two characters in a String? For example, "abcde" will become "bacde".

Answer 1

Since String objects are immutable, going to a char[] via toCharArray, swapping the characters, then making a new String from char[] via the String(char[]) constructor would work.

The following example swaps the first and second characters:

String originalString = "abcde";  char[] c = originalString.toCharArray();  // Replace with a "swap" function, if desired: char temp = c[0]; c[0] = c[1]; c[1] = temp;  String swappedString = new String(c);  System.out.println(originalString); System.out.println(swappedString); 

Result:

abcde bacde 

Answer 2

'In' a string, you cant. Strings are immutable. You can easily create a second string with:

 String second = first.replaceFirst("(.)(.)", "$2$1");