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JavaScript

Dan Emery
Dan Emery
13,841 Points
Posted by Dan Emery
Dan Emery
13,841 Points

Confused about JavaScript variables

A quick question that has me a little confused... How come the variable throws out an error when declared with parenthesis.... var quickLength = quick.length();

but works fine without var quickLength = quick.length;

I ask this because I though parenthesis were always needed after a method was declared??

=S

2 Answers

Aaron Graham
Aaron Graham
18,033 Points
Aaron Graham
Aaron Graham
18,033 Points

Assuming that "quick" is an array in your example, "length" is a property of an array, not a method like "pop()", or "splice()". It does get rather confusing at times. Your best bet is checking documentation when you run into issues like this. I usually use Mozilla.

Edit: To add some clarification, arrays are actually just objects. Think of them being structured like this:

var array = {
  length: 'some length',
  pop: function() {},
  splice: function() {}
  //... additional properties and methods
}

This obviously is just an example, but hopefully it helps understand the difference in how you use the object. When you reference something in the object that isn't a function, you don't use parenthesis.

Dan Emery
Dan Emery
13,841 Points
Dan Emery
Dan Emery
13,841 Points

ok, thanks for your help :)