How to delete a value from an array
This classic question pops up once in a while. Even the creator of Node.js Ryan Dahl asked this question from the audience during his Node.js presentation (an excellent one by the way).
How do I remove an element from an array?
delete operator of any use? There also exists funny named
, what about those? I want to modify the array in-place.
Use splice() to remove arbitrary item
The correct way to remove an item from an array is to use
splice(). It takes an index and amount of items to delete starting from that index.
Don't confuse this with its similar cousin
slice() that is used to extract a section of an array.
Use shift() and pop() if removing from the ends
If you're always interested in removing the first or the last item then you have an alternative solution. The methods
pop() exist precisely for this purpose.
Using delete creates empty spots
What ever you do, don't use
creates these kind of holes. It removes an item from the array but it does not update the length property. This leaves the array in a funny state that is best avoided.
Notice the empty spot and unchanged length.
The next time you need to remove something from an array, keep the following in mind.
|An item|| |
|First item|| |
|Last item|| |
|What about delete?||Try to avoid |