freaky-controls.md

Freaky Controls

These samples are a collection of extremely wrong-way implemented controls which were really used in production as some point!

If it is false then it is true!

The case was, allowing only numeric values in an input. The function checks the value, then returns false if the value is numeric (O.o)

How was it?

function OnlyNumericForText(obj, e) {
    var k;
    k = (e.which) ? e.which : e.keyCode;
    if (k >= 48 && k <= 57)
        return false;
    else
        return true;
}

$(".numeric").on('keypress', function (event) {
	return !OnlyNumericForText(this, event);
});

How could it be, plausible better solution(s)?

$(".numeric").on('keypress', function(e){
	return e.which === 8 || e.which === 0 || (e.which >= 48 && e.which <= 57);
});

In the original code;

• It returns false it the value is numeric. This is very confusing.
• Only numeric keys are allowed so, rather then letters, also, copying or cutting even deleting the value was forbidden.