709. To Lower Case

题目描述：

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"


解题思路：
还是直接看代码。

代码：

1 char* toLowerCase(char* str) {
2     for (int i = 0; str[i] != ''; ++i) {
3         if (str[i] >= 'A' && str[i] <= 'Z') {
4             str[i] = str[i] - ('A' - 'a');
5         }
6     }
7     return str;
8 }