How to add a new object (key-value pair) to an array in javascript?
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Solution 1
Use .push:
items.push({'id':5});
Solution 2
.push() will add elements to the end of an array.
Use .unshift() if need to add some element to the beginning of array i.e:
items.unshift({'id':5});
Demo:
items = [{'id': 1}, {'id': 2}, {'id': 3}, {'id': 4}];
items.unshift({'id': 0});
console.log(items);
And use .splice() in case you want to add object at a particular index i.e:
items.splice(2, 0, {'id':5});
// ^ Given object will be placed at index 2...
Demo:
items = [{'id': 1}, {'id': 2}, {'id': 3}, {'id': 4}];
items.splice(2, 0, {'id': 2.5});
console.log(items);
Solution 3
Sometimes .concat() is better than .push() since .concat() returns the new array whereas .push() returns the length of the array.
Therefore, if you are setting a variable equal to the result, use .concat().
items = [{'id': 1}, {'id': 2}, {'id': 3}, {'id': 4}];
newArray = items.push({'id':5})
In this case, newArray will return 5 (the length of the array).
newArray = items.concat({'id': 5})
However, here newArray will return [{'id': 1}, {'id': 2}, {'id': 3}, {'id': 4}, {'id': 5}].
Solution 4
New solution with ES6
Default object
object = [{'id': 1}, {'id': 2}, {'id': 3}, {'id': 4}];
Another object
object = {'id': 5};
Object assign ES6
resultObject = {...obj, ...newobj};
Result
[{'id': 1}, {'id': 2}, {'id': 3}, {'id': 4}, {'id': 5}];
Author by
exAres
Updated on December 08, 2020Comments
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exAres over 3 years
I have an array as :
items=[{'id':1},{'id':2},{'id':3},{'id':4}];
How should I add a new pair
{'id':5}
to the array?