Javascript / Backbone-使用索引删除数组对象

Question

Sorry if this is redundant, but I've searched through several Q&A's here but I still can't figure out what I'm doing wrong. I have an array saved as a backbone collection, and I need to delete an object from that array using its index:

deleteCartItem:  function(e) {
    var itemIndex = $(e.currentTarget).attr( "data-index" );
    console.log(itemIndex)
    console.log(this.collection)
    console.log(this.collection.length)
    var newCollection = this.collection.splice(itemIndex);
    console.log(newCollection.length);

},

Here is my Backbone Collection:

[Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object, Object]

Answer 1

splice actually modifies the collection, and returns the removed items. See the docs here:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice

Try this instead:

deleteCartItem:  function(e) {
    var itemIndex = $(e.currentTarget).attr( "data-index" );
    console.log(itemIndex)
    console.log(this.collection)
    console.log(this.collection.length)
    this.collection.splice(itemIndex, 1);
    console.log(this.collection.length);

},

Also note the howMany parameter.