JSFiddle - React, Tailwind, and code Playground

JavaScript

function match(string, pattern) {
    string = string.toLowerCase();
    pattern = pattern.toLowerCase();
    for (var i = 0, l = string.length; i < l; ++i) {
        if(pattern.indexOf(string[i]) === -1) return false;
    }
    return true;
}
alert(match("abcdef", "@C2D!"));