java中最常用反转字串的方法

ゝ一世哀愁。 2021-12-03 13:49 115阅读 0赞

Java中经常会用到将字符串进行反转的时候，程序员孔乙己总结了5种反转方法，如下：

public class Test {
        public static void main(String[] args) {
            System.out.println(reverse1("qwert"));
        }
    
        //方法1 递归方法
        public static String reverse1(String s) {
            int length = s.length();
            if (length <= 1){
                return s;
            }
            String left = s.substring(0, length / 2);
            String right = s.substring(length / 2, length);
            return reverse1(right) + reverse1(left);
        }
    
        //方法2 通过 charAt(int index)返回char值进行字符串拼接
        public static String reverse2(String s) {
            int length = s.length();
            String reverse = "";
            for (int i = 0; i < length; i++)
                reverse = s.charAt(i) + reverse;
            return reverse;
        }
        //方法3 把字符串转换成字符数组倒叙拼接然后返回值
        public static String reverse3(String s) {
            char[] array = s.toCharArray();
            String reverse = "";
            for (int i = array.length - 1; i >= 0; i--)
                reverse += array[i];
            return reverse;
        }
    
        //方法4 调用StringBuffer中的reverse方法
        public static String reverse4(String s) {
            return new StringBuffer(s).reverse().toString();
        }
    
        //方法5 把字符串转换成字符数组首位对调位置
        public static String reverse5(String orig) {
            char[] s = orig.toCharArray();
            int n = s.length - 1;
            int halfLength = n / 2;
            for (int i = 0; i <= halfLength; i++) {
                char temp = s[i];
                s[i] = s[n - i];
                s[n - i] = temp;
            }
            return new String(s);
        }
    }