13. Exchange first and last character in a String - prabhatrocks07/Core-Java-Programming GitHub Wiki

public class ReplaceFirstAndLast {

public static void main(String[] args) {
	String str = "Great India";
	System.out.println("-- The String is :--");
	System.out.println(str);
	
	String st = frontBack(str);
	System.out.println("-- After Replacing 1st & last character :--");
	System.out.println(st);
}

private static String frontBack(String str) {
	if(str == null || str.isEmpty()) {
		return null;
	} 
	
	char[] ch = str.toCharArray();
	char first = ch[0];
	ch[0] = ch[ch.length -1];
	ch[ch.length -1] = first;
	return new String(ch);
}

}