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JavaScript JavaScript Arrays Store Multiple Values in an Array Add Elements to an Array

Posted by Steve Fau
Steve Fau
5,622 Points

Pushing to an array declared as a const?

For example:

const items = [1, 'two'] items.push('three', 4) console.log(items.length) // 4

^ shouldn't that throw an error?

2 Answers

rydavim
rydavim
18,814 Points
rydavim
rydavim
18,814 Points

My understanding is that const in this example means the variable can't be reassigned not that you can't manipulate it. However, depending on the application it may or may not be good form - functional programming would likely discourage mutating the array.

Let me know if that doesn't answer your question and I can look into it more deeply. Happy coding!

Steve Fau
Steve Fau
5,622 Points

Thanks a lot :)

Yeah I guess one has to differentiate between reassigning and manipulating. I'll also do some more reading :)

Anastasios Poursaitedes
Anastasios Poursaitedes
10,491 Points
Anastasios Poursaitedes
Anastasios Poursaitedes
10,491 Points

The const keyword doesn't allow reassignment, which means that you cannot reassign the array with some other data(assign a string to it for example). That doesn't mean that you can't mutate the elements of the array. You can remove, add new elements and change existing elements in the array. The array's contents remain mutable.