Leetcode709. To Lower Case

Posted 2020-12-25 DCREN

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"

Discuss

直接遍历就可以

Code

class Solution {
    public String toLowerCase(String str) {
        if (str == null || str.length() == 0) { return null; }
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < str.length(); i++) {
            char c = str.charAt(i);
            if (c >= ‘A‘ && c <= ‘Z‘) {
                c += 32;
                sb.append(Character.toString((char)c));
                continue;
            }
            sb.append(c);
        }
        return sb.toString();
    }
}