locutus/esm/c/ctype/isalnum.js

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

export function isalnum(c) {
    //      discuss at: https://locutus.io/c/ctype/isalnum/
    // parity verified: C 23
    //     original by: Kevin van Zonneveld (https://kvz.io)
    //          note 1: Checks if the character is alphanumeric (A-Z, a-z, or 0-9).
    //       example 1: isalnum('A')
    //       returns 1: true
    //       example 2: isalnum('5')
    //       returns 2: true
    //       example 3: isalnum('_')
    //       returns 3: false
    c = (c + '').charAt(0);
    return /^[A-Za-z0-9]$/.test(c);
}