JSFiddle - React, Tailwind, and code Playground

by f0t0n

HTML

<input type="text" id="input1" />
<input type="text" id="input2" />

<script type="text/javascript">
    var maxLen = 6,
        helpCodes = [37, 39, 8, 9], // left and right arrows, backspace, tab
        codes = [];
    for(var code = 48; code < 58; code++) { // number keys (48-57)
        codes.push(code);
    }
    $('#input1,#input2').on('keydown', function (e) {
        if(helpCodes.indexOf(e.keyCode) > -1) {
            return true;
        }
        if(e.shiftKey || this.value.length == maxLen
                || codes.indexOf(e.keyCode) < 0 ) {
            return false;
        }
    });
</script>