Array.size() vs Array.length
What is the difference between the two?
So I know that array.size() is a function while array.length is a property. Is there a usecase for using one over the other? Is one more efficient? (I would imagine .length to be significantly faster as it is a property rather then a method call?) Why would one ever use the slower option? Are there some browsers that are incompatible with one or the other?
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Array.size() is not a valid method
Always use the length property
There is a library or script adding the size method to the array prototype since this is not a native array method. This is commonly done to add support for a custom getter. An example of using this would be when you want to get the size in memory of an array (which is the only thing I can think of that would be useful for this name).
Underscore.js unfortunately defines a
size method which actually returns the length of an object or array. Since unfortunately the length property of a function is defined as the number of named arguments the function declares they had to use an alternative and size was chosen (count would have been a better choice).
.size() is not a native JS function of
Array (at least not in any browser that I know of).
.length should be used.
.size() does work on your page, make sure you do not have any extra libraries included like prototype that is mucking with the
There might be some plugin on your browser that is mucking with the
.size() function is available in Jquery and many other libraries.
.length property works only when the index is an integer.
length property will work with this type of array:
var nums = new Array(); nums = 1; nums = 2; print(nums.length); // displays 2
length property won’t work with this type of array:
var pbook = new Array(); pbook["David"] = 1; pbook["Jennifer"] = 2; print(pbook.length); // displays 0
So in your case you should be using the
.size() is jQuery’s, much probably you’re either confusing with or took from someone else who had imported the jQuery library to his project.
If you’d have jQuery imported and you’d write like
$(array).size(), it would return the array length.
array.length isn’t necessarily the number of items in the array:
var a = ['car1', 'car2', 'car3']; a = 'car100'; a.length; // 101
The length of the array is one more than the highest index.
As stated before
Array.size() is not a valid method.
The .size() method is deprecated as of jQuery 1.8. Use the .length property instead