Question

How to swap adjacent characters of a string in Java

Answer 1

public class MyClass {
    private static String swap_adjacent_characters(String str) {
        int length = str.length();
        char[] arr = str.toCharArray();
     
        if (length % 2 == 0) {
            for (int i = 0; i < length; i += 2) {
                char tmp = arr[i];
                arr[i] = arr[i + 1];
                arr[i + 1] = tmp;
            }
        }
         
        return new String(arr);
    }
     
    public static void main(String args[]) {
        String str = "ABCDEFGH";
     
        str = swap_adjacent_characters(str);
 
        System.out.print(str);
    }
}
 
  
 
 
 
/*
run:
 
BADCFEHG
  
*/

 

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Answer 2

public class MyClass {
    private static String swap_adjacent_characters(String str) {
    	int length = str.length();
    	StringBuilder sb = new StringBuilder(str);
    
    	if (length % 2 == 0) {
    		for (int i = 0; i < length; i += 2) {
                char left = sb.charAt(i);
                char right = sb.charAt(i + 1);
            
                sb.setCharAt(i, right);
                sb.setCharAt(i + 1, left);
    		}
    	}
    	
    	return sb.toString();
    }
    
    public static void main(String args[]) {
      	String str = "ABCDEFGH";
    
    	str = swap_adjacent_characters(str);

    	System.out.print(str);
    }
}






/*
run:

BADCFEHG
 
*/

 

70+ SQL courses for beginners and professionals