Use parameter of a function as the key to get the value from an array

Question

I have a javascript/jQuery setup where a page name is given. A function should then take this, get the html data of the page and alert it.

HTML

var page = $(this).attr('id');
viewPage(page);

function viewPage(page) {
    var html = pages.page;
    alert(html);
}

var pages = {
    page1: 'Content of page.....',
    [etc...]
}

However, the variable html is always returning as undefined. When I manually access the page from the pages array it works fine. What's the issue?

Thanks in advance!

`pages[page]` will work better or if id is a digit `pages["page"+id]` — mplungjan, May 02 '15 at 15:39

score 4 · Accepted Answer · answered May 02 '15 at 15:38

4

Your argument has to be evaluated as a key of your pages object.

Try:

function viewPage(page) {
  var html = pages[page];
  alert(html);
}

When you use pages.page it looks for the key 'page'. Wheras when you do pages[page] it evaluates your page argument to whatever it equals, and looks for that key on pages.

answered May 02 '15 at 15:38

Mike Driver

8,481
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Works perfectly, thank you! I'll accept this when I can. Thanks! – user3002189 May 02 '15 at 15:41

score 1 · Answer 2 · answered May 02 '15 at 15:40

1

First, pages is not an array, it's a javascript plain object.

Secondly, you need to use associative notation, not dot notation.

function viewPage(page) {
    var html = pages[page];
    alert(html);
}

answered May 02 '15 at 15:40

Roamer-1888

19,138
5
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Use parameter of a function as the key to get the value from an array

2 Answers2