Can i shorthand these ‘if statements’?

[JohnMotylJr]

Howdy, is there any kind of ternary or shorthand method for this. Maybe even a switch case?

$document.on({

keydown: function(event) {

// F5

if (event.which == 116) { return true; }

// Ctrl + A

if ((event.ctrlKey && event.which == 097) || (event.ctrlKey && event.which == 65)) { return true; }

// Ctrl + X

if ((event.ctrlKey && event.which == 120) || (event.ctrlKey && event.which == 88)) { return true; }

// Ctrl + C

if ((event.ctrlKey && event.which == 099) || (event.ctrlKey && event.which == 67)) { return true; }

// Ctrl + Z

if ((event.ctrlKey && event.which == 122) || (event.ctrlKey && event.which == 90)) { return true; }

// Ctrl + V

if ((event.ctrlKey && event.which == 118) || (event.ctrlKey && event.which == 86)) { return true; }

//.... etc

[Mottie]

Hi John!

I’m sure there is an even more efficient way than this method (maybe using a for in loop), but this is what I came up with (demo):

var allowed = {

key: [116],

ctrl: [65, 67, 86, 88, 90, 97, 99, 118, 120, 122],

alt: []

};



$(document).on({

keydown: function(event) {

var k = event.which;

// regular key

if ($.inArray(k, allowed.key) >= 0) {

return true;

}

// ctrl keys

if (event.ctrlKey && $.inArray(k, allowed.ctrl) >= 0) {

return true;

}

// alt keys - added just in case ;)

if (event.altKey && $.inArray(k, allowed.alt) >= 0) {

return true;

}

}

});​

[JohnMotylJr]

@Mottie

I am totally going to check this out now.

I am somewhat new to the whole js / jQuery thang but is there any way to test javascript / jQuery code for efficiency? Because whether i run this as a loop, if stack, switch case, on vs live vs keydown etc, Im not sure if im trying to make this more difficult on myself.

[Mottie]

I agree with Jamy, don’t worry too much about efficiency. If it runs fast enough in IE7 then it’s good.

I just realized the thing that is missing in the code… it needs a filter to allow alphabetic keys through and a return false at the end (demo).

var allowed = {

key: [116],

ctrl: [65, 67, 86, 88, 90, 97, 99, 118, 120, 122],

alt: []

};



$(document).on({

keydown: function(event) {

var k = event.which;

// regular key

if ($.inArray(k, allowed.key) >= 0) {

log('allowed ' + k);

return true;

}

if (event.ctrlKey && $.inArray(k, allowed.ctrl) >= 0) {

log('allowed ctrl+' + k);

return true;

}

if (event.altKey && $.inArray(k, allowed.alt) >= 0) {

log('allowed alt+' + k);

return true;

}

// allow 0-9, a-z and A-Z

if ((!event.ctrlKey || !event.altKey) &&

(k >= 48 && k <= 57) ||

(k >= 65 && k <= 90) ||

(k >= 97 && k <= 122)) {

log('allowed ' + k);

return true;

}

return false;

}

});​

[Author]

Posts