Question

I have the following function

$('.link1-**number**').click( function() {
    $(".link2-**number**").hide()
});

When I click on link1-number I want to hide link2-number but only if number are the same value.

So
<a class="link1-1987">Link 1</a>
Hides <a class="link2-1987">Link 2</a>

<a class="link1-1">Link 1</a>
Hides <a class="link2-1">Link 2</a>

<a class="link1-5">Link 1</a>
Hides <a class="link2-5">Link 2</a>

etc

Answer 1

Answer for your edit:

$('a[class^=link1]').click(function(){
    var number = this.className.split('-')[1];
    $('a.link2-' + number).hide();
});

DEMO

Note that it will work only if:

1. There is only one class for link1 anchors.
2. That anchor doesn’t have more than one hyphen.