javascript - Array.slice on array with one element - Stack Overflow

admin管理员组

文章数量:1426637

I'm really confused by this. If I do something like this:
[1].slice(1)
it returns an empty array (in the chrome interactive console). But if I pare:
[1].slice(1) === []
it's always false. So my Question is, what does [1].slice(1) really return?

I'm really confused by this. If I do something like this:
[1].slice(1)
it returns an empty array (in the chrome interactive console). But if I pare:
[1].slice(1) === []
it's always false. So my Question is, what does [1].slice(1) really return?

• javascript
• arrays
• slice

Share Improve this question Follow edited Aug 13, 2012 at 20:13 LOZ 1,17722 gold badges1616 silver badges4646 bronze badges asked Aug 13, 2012 at 16:49 rabrarabra 75611 gold badge66 silver badges1111 bronze badges 2

• 1 What are you trying to do? There is nothing to slice at index 1 – Esailija Commented Aug 13, 2012 at 16:52
• writing a lispy to javascript piler and trying to translate (rest '(1)). – rabra Commented Aug 13, 2012 at 16:58

Add a ment  | 

4 Answers 4

Sorted by: Reset to default 8

=== pares objects by references.
You're paring two different array objects which are both empty.

If you want to check whether an array is empty, check whether .length === 0.

That's not a problem of slice or ===.

If you do [1]==[1], it returns false.

That's because both == and === pare objects by reference

[] === [] also returns false. [1].slice(1) does in fact return []

You better check the length:

[1].slice(1).length; // falsey

本文标签： javascriptArrayslice on array with one elementStack Overflow