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# 709. To Lower Case

## Question 709

<https://leetcode.com/problems/to-lower-case/description/>

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"
```

### Answer By C <a href="#answer" id="answer"></a>

```c
char* toLowerCase(char* str) {
    int i = 0;
    while(str[i]){
        if(str[i] >= 'A' && str[i] <= 'Z'){
            str[i] += 'a' - 'A';
        }
        i++;
    }
    return str;
}
```