Why doesn't splicing an object from an array in Javascript return the array? - Stack Overflow

admin管理员组

文章数量:1403217

I have an array of objects (say, a deck of cards):

var deck = [];
deck.push(new Card(suit, rank));

The following seems to work:

var card = deck.pop();
var card = deck.shift();

(pulling from the "top" or "bottom" of the deck respectively)

But if I want a card from the middle (say, if this was a hand of cards)

var card = deck.splice(2,1);

The object doesn't seem to get properly assigned to the variable (everything is undefined). Everything I look up says that splice should return the object that I'm removing - what am I missing?

I have an array of objects (say, a deck of cards):

var deck = [];
deck.push(new Card(suit, rank));

The following seems to work:

var card = deck.pop();
var card = deck.shift();

(pulling from the "top" or "bottom" of the deck respectively)

But if I want a card from the middle (say, if this was a hand of cards)

var card = deck.splice(2,1);

The object doesn't seem to get properly assigned to the variable (everything is undefined). Everything I look up says that splice should return the object that I'm removing - what am I missing?

• javascript
• arrays

Share Improve this question Follow asked Jun 7, 2012 at 16:38 Allen GouldAllen Gould 14177 bronze badges

Add a ment  | 

4 Answers 4

Sorted by: Reset to default 8

Try

var card = deck.splice(2,1)[0];

Since splice returns an array of the removed elements...

splice returns an array of possible removed elements, so if you remove only one element you still have an array. So:

var card = deck.splice(2, 1)[0];

splice should return an array containing the element you removed. The actual element can be obtained like:

var card = deck.splice(2,1)[0];

Just the same error as here (even a quite similiar environment :-): .splice() returns an Array of the removed elements, not a single element. So you will need to get the first element of that array:

var card = deck.splice(2,1)[0];

本文标签： Why doesn39t splicing an object from an array in Javascript return the arrayStack Overflow