344. 反转字符串

思路1:转换成char数组，然后做数组的反转，

class Solution {
    public String reverseString(String s) {
        char[] ch=s.toCharArray();
        for(int i=0;i<ch.length/2;i++){
            char temp=ch[i];
            ch[i]=ch[ch.length-1-i];
            ch[ch.length-1-i]=temp;
        }
        String result = new String(ch);
        return result;
    }
}