java实现字符串反转的6种方法

package com.mplus;

import java.util.Stack;

/**
* Created by alex on 16-5-15.
*/
public class ReverseStringDemo {
static String reverseM1(String str) {
StringBuffer sb = new StringBuffer();
for (int i = str.length() - 1; i >= 0; i --) {
sb.append(str.charAt(i));
}

return sb.toString();
}
static String reverseM2(String str) {
StringBuffer reverse = new StringBuffer();

Stack stack = new Stack();
for (int i = 0; i < str.length(); i ++) {
stack.push(str.charAt(i));
}

while (!stack.isEmpty()) {
reverse.append(stack.pop());
}

return reverse.toString();
}

static String reverseM3(String str) {
StringBuffer sb = new StringBuffer(str);
return sb.reverse().toString();
}

/**
* 折半反转
* @param str
* @return
*/
static String reverseM4(String str) {
int start = 0;
int end = str.length() - 1;

char[] cArr = str.toCharArray();

while(start < end) {
char c = cArr[end];
cArr[end] = cArr[start];
cArr[start] = c;
start ++;
end --;
}
return new String(cArr);
}

/**
* 采用异或
* @param str
* @return
*/
static String reverseM5(String str) {
char[] cArr = str.toCharArray();

int start = 0, end = cArr.length - 1;

for (;start < end; start ++, end --) {
cArr[start] ^= cArr[end];//采用异或
cArr[end] ^= cArr[start];
cArr[start] ^= cArr[end];
}

return new String(cArr);
}

/**
* 采用递归
* @param str
* @return
*/
static String reverseM6(String str) {
if (str.length() == 1) {
return str;
}

return reverseM6(str.substring(1)) + str.substring(0,1);
}

public static void main(String[] args) {
System.out.println(reverseM1("abcdef"));
System.out.println(reverseM2("abcdef"));
System.out.println(reverseM3("abcdef"));
System.out.println(reverseM4("abcdef"));
System.out.println(reverseM5("abcdef"));
System.out.println(reverseM6("abcdef"));
}
}
[code="java"][/code]