Amazing Functions in JavaScript

[magicyte]

Here is one amazing function that is a use in JavaScript that one may LOVE to use instead of document.getElementById():

<!-- Makes coding SO much easier -->
function getObj(obj)
{
if(document.all)            return document.all[obj];
else if(document.layers) return document.layers[obj];
}

I may have accidently reused it, but I have some others that you guys might like:

<!-- These are plain stealing and calling them your own, however it is convenient in writing shorter code -->
function random()
{
return Math.random();
}

function acos(int)
{
return Math.acos(int);
}

<!-- Love these -->
function setVal(obj,str)
{
getObj(obj).value = str;
}

function setHtml(obj,str)
{
getObj(obj).innerHTML = str;
}

See what functions can do for you? Feel free to take these and make them your own. Change 'em up too!

-magicyte

[jscheuer1]

Here is one amazing function that is a use in JavaScript that one may LOVE to use instead of document.getElementById():

I can't see why, neither of those two methods are required in version 5+ browsers. No current browser uses document.layers, and if you were to have some antique around that did, it should be the first test, not the second as you have it there - to avoid possible errors.

Seems like a bit of extra typing at first to save little, combined with having to memorize the other way to do things. In the case of the first one, it will fail to retrieve the element in many cases due to its lack of support for document.getElementById(). And it really isn't getting an object (when it works at all) as its name implies unless that object happens to be an element.

Functions are great if they work, but generally more than a few lines are required to deliver much utility.

[magicyte]

I am sorry if what I posted isn't useful for those of you with IE 5+ (I have IE 4 w/ WINDOWS XP). I just posted it because I find it easier to use than document.getElementById(), considering I use it a lot.

You are right. getObj doesn't get an object. But, man oh man, I wish that JavaScript was compiled so that everything could be compatible with other browser applications.

-magicyte

[mburt]

I find it easier to use than document.getElementById(), considering I use it a lot.

I just define this at the beginning of my file:

var $ = function(e) {return document.getElementById(e);};

Simple.

[magicyte]

Does it involve PHP? I noticed you used $...

-magicyte

[codeexploiter]

Does it involve PHP? I noticed you used $...

-magicyte

You can declare a variable in JS whose name is $ need not be in PHP

[jscheuer1]

I have IE 4 w/ WINDOWS XP

Um, Windows XP came with IE 6 I think, at least 5 or 5.5, what happened? Most pages on the web won't render well, if at all in IE 4, and most scripts will either not work, or will degrade to a very simplistic level. IE 4 will often report script errors on pages that technically have none. Many commercial sites require at least IE 5.5 if you are using IE. How on earth do you get by with such a relic?

[Twey]

I just posted it because I find it easier to use than document.getElementById(), considering I use it a lot.

You shouldn't. Both the methods it is capable of using to look up an element are deprecated. You should use document.getElementById(). You may assign a reference with a shorter name if you like. However, that name should not be $.

You can declare a variable in JS whose name is $ need not be in PHP

You can, but should not. Use of the $ character in identifiers is reserved for machine-generated code (ECMA-262 section 7.6).

My own favourite utility functions are:

function map(f, a) {
  for (var i = a.length - 1, r = []; i >= 0; --i)
    r[i] = f(a[i], i);

  return r;
}

function filter(f, a) {
  if (typeof f === "string")
    f = (function(f) {
      return function(a) {
        return !!a[f];
      };
    })(f);

  for (var i = 0, r; i < a.length; ++i)
    if (f(a[i]))
      r.push(a[i]);

  return r;
}

function reduce(f, a, t) {
  if (!a.length)
    return t;

  t = t || a[0];

  for (var i = 0, n = a.length; i < n; ++i)
    t = f(t, a[i]);

  return t;
}

function compose(f1, f2) {
  return function() {
    return f1(f2.apply(this, Array.prototype.slice.call(arguments)));
  };
}

function bind(obj, fun, args) {
  return function() {
    if (obj === true)
      obj = this;

    var f = typeof fun === "string" ? obj[fun] : fun;

    return f.apply(obj, Array.prototype.slice.call(args || [])
        .concat(Array.prototype.slice.call(arguments)));
  };
}

... as well as a bunch of curryable operator functions. I have a few more, nicely modularised, but they're all on my desktop, which is currently kaput. If I found myself using many of these, I suspect I would switch over to the Functional Javascript library.

[clueful]

<!-- Makes coding SO much easier -->
function getObj(obj)
{
if(document.all)            return document.all[obj];
else if(document.layers) return document.layers[obj];
}

Have you ever used anything but I.E.? The above function would return undefined in Mozilla and others.

function random()
{
return Math.random();
}

function acos(int)
{
return Math.acos(int);
}

These are pointless and only de-objectify an object orientated language.

<!-- Love these -->
function setVal(obj,str)
{
getObj(obj).value = str;
}

function setHtml(obj,str)
{
getObj(obj).innerHTML = str;
}

See what functions can do for you?

Absolutely nothing; The phrase "ashtray on a motorbike" comes to mind.

[mburt]

You can, but should not. Use of the $ character in identifiers is reserved for machine-generated code (ECMA-262 section 7.6).

Okay, that's fair. But can you show me an example of the machine-generated reserved code?