Using JavaScript how can I remove an object from an array and return that object? For example, change this:
[{first:"John", last:"Smith"}]
...to this:
{first:"John", last:"Smith"}
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2You will have to show a little more context of the variable construction for a complete answer. Is this array assigned to a variable by itself or part of some other object?jfriend00– jfriend002015-07-30 18:06:33 +00:00Commented Jul 30, 2015 at 18:06
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@jfriend00 It's assigned to a variable by itself - Plunker added.Ryan– Ryan2015-07-30 18:55:54 +00:00Commented Jul 30, 2015 at 18:55
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2 Answers
Use splice. It will remove some items from the array and return them.
var data = [{first:"John", last:"Smith"}];
var extract = data.splice(0, 1);
console.log(extract, data); // will print: {first..., last...}, []
Note that splice does return an array itself, so you'll have to take the appropriate elements from that.
If you only have a single element, you can splice, pop, or simply take the element by index and then truncate the array.
7 Comments
Ryan
.splice is returning an array with an object (not just an object). Am I missing something? Compare to myObject: plnkr.co/edit/Pg3rLv2Lspj118i34EBa?p=preview
ssube
@Ryan I mentioned that in the answer.
splice will remove the elements from the original array and return a new array, which you have to take the element from normally (data.splice(0, 1)[0] or the like). It does the important step of removing, especially since it can remove element(s) from the middle of another array efficiently.Ryan
So that's my question, how can I return just an object (not an array with an object)? I'm getting
undefined when I try .pop(): plnkr.co/edit/Pg3rLv2Lspj118i34EBa?p=previewssube
You can use
data.splice(0, 1).pop() or data.splice(0, 1)[0] or any number of other methods. There is no built-in method (that I know of) to splice a single element out of an array and return it as an object, probably because that behavior wouldn't make sense for multiple elements.Ryan
data.splice(0, 1).pop(); and data.splice(0, 1)[0] both return undefined plnkr.co/edit/Pg3rLv2Lspj118i34EBa?p=preview |
You could use the pop() method. It will always remove the last element from array and handle it to you;
Example:
var myArray = [{first:"John", last:"Smith"}]
var myObject = myArray.pop()
Now your myObject value will be {first:"John", last:"Smith"} and your myArray will be empty
If you had more than one items:
var myArray = [{first:"John", last:"Smith"}, {first:"Test", last:"Now"}]
var myObject = myArray.pop()
What happens here is that your myArray will have just the first value and the myObject will have the last one {first:"Test", last:"Now"}
You could also take a look at splice()
