Array index of functions

Question

I am trying to create an array that acts like the contents page of a book. Here is what I'm trying:

var section = [someFunction(pInput.value), anotherFunction(pInput.value), function3(pInput.value)];
var sectionNum = 0;

var playerInput = function () {
    var pInput = document.getElementById('input');
    section[sectionNum];
};

EDIT: My functions wont execute, so when I run the code nothing happens.

To sum up, I want to know if I'm coding it wrong or if there is another way to do it.

Thanks for the help, ~Gateway

I think your functions will execute when you define your array, not when you try to call them inside your playerInput function. — putvande
– putvande, Commented Jan 6, 2014 at 23:11

Ray Toal · Accepted Answer · 2014-01-06 23:13:41Z

3

You should restructure your code along these lines:

var section = [someFunction, anotherFunction, function3];

var sectionNum = 0;

var playerInput = function () {
    var pInput = document.getElementById('input');
    section[sectionNum](pInput.value);
};

But please be sure to put in some nice checks that sectionNum has a legal value at all times.

answered Jan 6, 2014 at 23:13

Ray Toal

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MT0 · Accepted Answer · 2014-01-06 23:14:01Z

1

The section array is storing the values returned by each function rather than the functions themselves.

You probably meant to do something like this:

var section = [someFunction, anotherFunction, function3];
var sectionNum = 0;

var playerInput = function () {
    var pInput = document.getElementById('input');
    section[sectionNum](pInput.value);
};

answered Jan 6, 2014 at 23:14

MT0

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Kristian Barrett · Accepted Answer · 2014-01-06 23:16:31Z

1

Instead of putting your functions inside of an array and trying to call them from there based on the sectionNum. You could use a switch statement; which in my opinion makes it easier to read:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/switch

In your case it would be something like:

switch (sectionNum) {
  case 0:
    someFunction(pInput.value)
    break;
  case 1:
    anotherFunction(pInput.value)
    break;
  case 2:
    function3(pInput.value)
    break;
  default:
    alert("I don't know that number")
    break;
}

The only downside is that you can't add more functions on the go as you can with the array.

answered Jan 6, 2014 at 23:16

Kristian Barrett

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