Reverse a String

1) Using StringBuffer class.

StringBuffer sbf = new StringBuffer("Reverse this");
System.out.println(sbf.reverse());

2) Using iterative method.

String str = "Reverse this";
char[] strArray = str.toCharArray();
for (int i = strArray.length - 1; i >= 0; i--)
{
    System.out.print(strArray[i]);
}

3) Using recursive method.

static String recursiveMethod(String str)
{
     if ((null == str) || (str.length() <= 1))
     {
            return str;
     }
     return recursiveMethod(str.substring(1)) + str.charAt(0);
}


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public class ReverseString {

    public static void main(String[] args) {
//      1)Using StringBuffer class.
        StringBuffer sbf = new StringBuffer("Reverse this");
        System.out.println(sbf.reverse());

//      2) Using iterative method.
        String str = "Reverse this";
        char[] strArray = str.toCharArray();
        for (int i = strArray.length - 1; i >= 0; i--)
        {
            System.out.print(strArray[i]);
        }

//      3) Using recursive method.
        recursiveMethod("Reverse this");
    }

    static String recursiveMethod(String str)
    {
        if ((null == str) || (str.length() <= 1))
        {
            return str;
        }
        return recursiveMethod(str.substring(1)) + str.charAt(0);
    }
}

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