string reversre in java code example

Example 1: java reverse a string

// Library approach
public static String solution(String str) {
	// StringBuilder is not thread-safe, use StringBuffer
	return new StringBuffer(str).reverse().toString();
}

// DIY approach
public static String solution(String str) {
	char[] chars = str.toCharArray();
	for(int i = 0, j = str.length() - 1; i < j; i++, j--) {
		char ch = chars[i];
		chars[i] = chars[j];
		chars[j] = ch;
	}
	return new String(chars);
}

Example 2: java string reverse

String str = "Reverse this strings";
//for loop
for (int i = str.length() - 1; i >= 0; i--) {
	System.out.print(str.charAt(i));
}

// StringBuffer for multi thread
StringBuffer sb = new StringBuffer(); 
sb.append(str);
System.out.print(sb.reverse().toString());

// StringBuffer for single thread
StringBuilder sb = new StringBuilder(); 
sb.append(str);
System.out.print(sb.reverse().toString());