709. 转换成小写字母

题目来源

LEETCODE

题目描述

题目解析

解法1

import java.util.*;

public class Solution {
    public static String toLowerCase(String str) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < str.length(); i++){
            // 并将该字符串中的大写字母转换成小写字母
            char c = str.charAt(i);
            if (c >= 'A' && c <= 'Z'){
                char t = (char)(c + 32);  // 易错点
                sb.append(t);
            }else{
                sb.append(c);
            }
        }

        return sb.toString();
    }


    public static void main(String[] args) {
        System.out.println(toLowerCase("AAALVFREe12"));
    }
}

解法2

public class Solution {
    public static String toLowerCase(String str) {
        char[] arr =  str.toCharArray();
        for (int i = 0; i < arr.length; i++){
            if (arr[i] >= 'A' && arr[i] <= 'Z'){
                arr[i] = (char)(arr[i] + 32);
            }
        }
        return String.valueOf(arr);
    }


    public static void main(String[] args) {
        System.out.println(toLowerCase("AAALVFREe12"));
    }
}