rspec/rules/S2870/javascript/rule.adoc

== Why is this an issue?

The ``++delete++`` operator can be used to remove a property from any object. Arrays are objects, so the ``++delete++`` operator can be used here too, but if it is, a hole will be left in the array because the indexes/keys won't be shifted to reflect the deletion. 


The proper method for removing an element at a certain index would be:

* ``++Array.prototype.splice++`` - add/remove elements from the array 
* ``++Array.prototype.pop++`` - add/remove elements from the end of the array 
* ``++Array.prototype.shift++`` - add/remove elements from the beginning of the array


=== Noncompliant code example

[source,javascript]
----
var myArray = ['a', 'b', 'c', 'd'];

delete myArray[2];  // Noncompliant. myArray => ['a', 'b', undefined, 'd']
console.log(myArray[2]); // expected value was 'd' but output is undefined
----


=== Compliant solution

[source,javascript]
----
var myArray = ['a', 'b', 'c', 'd'];

// removes 1 element from index 2
removed = myArray.splice(2, 1);  // myArray => ['a', 'b', 'd']
console.log(myArray[2]); // outputs 'd'
----



ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Remove this use of "delete".


'''
== Comments And Links
(visible only on this page)

=== on 28 Apr 2015, 15:33:29 Ann Campbell wrote:
back to you [~linda.martin]

You didn't have any languages targeted. I assumed JavaScript...

=== on 29 Apr 2015, 09:02:41 Linda Martin wrote:
\[~ann.campbell.2] Indeed thanks!

I updated the comment in the code snippet to show how the array look like after the deleting the element. I let you remove it or update if you think it is to heavy and not necessary.

=== on 29 Apr 2015, 09:09:47 Ann Campbell wrote:
Your updated looks good to me [~linda.martin]. I just modified it's place in the code slightly.

=== on 29 Apr 2015, 11:41:26 Linda Martin wrote:
Perfect this way! Thanks.

endif::env-github,rspecator-view[]