使用charAt()方法

    String name = "gaurav";
    String reversedString = "";
    
    for(int i = name.length()-1; i>=0; i--){
      reversedString = reversedString + name.charAt(i);
    }
    System.out.println(reversedString);

使用toCharArray()方法

String name = "gaurav";
    char [] stringCharArray = name.toCharArray();
    String reversedString = "";
    
    for(int i = stringCharArray.length-1; i>=0; i--) {
      reversedString = reversedString + stringCharArray[i];
    }
    System.out.println(reversedString);

使用Stringbuilder的reverse()方法

    String name = "gaurav";
    
    String reversedString = new StringBuilder(name).reverse().toString();
    
    System.out.println(reversedString);

检查https://coderolls.com/reverse-a-string-in-java/

System.out.print("Please enter your name: ");
String name = keyboard.nextLine();

String reverse = new StringBuffer(name).reverse().toString();
String rev = reverse.toLowerCase();
System.out.println(rev);

我使用这种方法将名称反向转换为小写。

递归:

 public String stringReverse(String string) {
    if (string == null || string.length() == 0) {
        return string;
    }
    return stringReverse(string.substring(1)) + string.charAt(0);
 }

由于下面的方法(使用XOR)反转字符串没有列出，我附加这个方法来反转字符串。

该算法基于:

1.(a xor b) xor b = a 2.(a xor b) xor a = b

代码片段:

public class ReverseUsingXOR {
    public static void main(String[] args) {
        String str = "prateek";
        reverseUsingXOR(str.toCharArray());
    }   

    /*Example:
     * str= prateek;
     * str[low]=p;
     * str[high]=k;
     * str[low]=p^k;
     * str[high]=(p^k)^k =p;
     * str[low]=(p^k)^p=k;
     * 
     * */
    public static void reverseUsingXOR(char[] str) {
        int low = 0;
        int high = str.length - 1;

        while (low < high) {
            str[low] = (char) (str[low] ^ str[high]);
            str[high] = (char) (str[low] ^ str[high]);   
            str[low] = (char) (str[low] ^ str[high]);
            low++;
            high--;
        }

        //display reversed string
        for (int i = 0; i < str.length; i++) {
            System.out.print(str[i]);
        }
    }

}

输出:

keetarp

对于不允许StringBuilder或StringBuffer的Online Judges问题，可以使用char[]，如下所示:

public static String reverse(String input){
    char[] in = input.toCharArray();
    int begin=0;
    int end=in.length-1;
    char temp;
    while(end>begin){
        temp = in[begin];
        in[begin]=in[end];
        in[end] = temp;
        end--;
        begin++;
    }
    return new String(in);
}

    public String reverse(String s) {

        String reversedString = "";
        for(int i=s.length(); i>0; i--) {
            reversedString += s.charAt(i-1);
        }   

        return reversedString;
    }