[LeetCode] 709. To Lower Case

Problem
Implement function ToLowerCase() that has a string parameter str, and returns the same string in lowercase.
Example 1:
Input: “Hello”Output: “hello”Example 2:
Input: “here”Output: “here”Example 3:
Input: “LOVELY”Output: “lovely”
Solution
class Solution {
public String toLowerCase(String str) {
char[] chs = str.toCharArray();
for (int i = 0; i < chs.length; i++) {
char ch = chs[i];
if ((int)ch >= 65 && (int)ch <= 90) chs[i] += 32;
}
return new String(chs);
}
}
//a: 97, z: 122
//A: 65, Z: 90