Solution 1

Python3

class Solution:
    def toLowerCase(self, s: str) -> str:
        return "".join([chr(ord(c) | 32) if c.isupper() else c for c in s])

Java

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

C++

class Solution {
public:
    string toLowerCase(string s) {
        for (char& c : s) {
            if (c >= 'A' && c <= 'Z') {
                c |= 32;
            }
        }
        return s;
    }
};

Go

func toLowerCase(s string) string {
    cs := []byte(s)
    for i, c := range cs {
        if c >= 'A' && c <= 'Z' {
            cs[i] |= 32
        }
    }
    return string(cs)
}

TypeScript

function toLowerCase(s: string): string {
    return s.toLowerCase();
}

Rust

impl Solution {
    pub fn to_lower_case(s: String) -> String {
        s.to_ascii_lowercase()
    }
}

C

char* toLowerCase(char* s) {
    int n = strlen(s);
    for (int i = 0; i < n; i++) {
        if (s[i] >= 'A' && s[i] <= 'Z') {
            s[i] |= 32;
        }
    }
    return s;
}

Problem