locutus/esm/c/ctype/toupper.js

Locutus other languages' standard libraries to JavaScript for fun and educational purposes

export function toupper(c) {
    //      discuss at: https://locutus.io/c/ctype/toupper/
    // parity verified: C 23
    //     original by: Kevin van Zonneveld (https://kvz.io)
    //          note 1: Converts a lowercase letter to uppercase.
    //       example 1: toupper('a')
    //       returns 1: 'A'
    //       example 2: toupper('A')
    //       returns 2: 'A'
    //       example 3: toupper('5')
    //       returns 3: '5'
    c = (c + '').charAt(0);
    return c.toUpperCase();
}