Adding items to an object through the .push() meth

问题:

I'm doing a loop through few input elements of 'checkbox' type. After that, I'm adding values and checked attributes to an array. This is my code:

var stuff = {};
$('form input[type=checkbox]').each(function() {
    stuff[$(this).attr('value')] = $(this).attr('checked');
});

This works fine, but I'm just wondering if I can do the exact same thing with .push() method in Jquery?

I've tried something like this but it doesn't work:

stuff.push( {$(this).attr('value'):$(this).attr('checked')} );

Edit:

I was trying to use .push() method on Object, but .push() is actually just a method of Array Object.

回答1:

.push() is a method of the Built-in Array Object

It is not related to jQuery in any way.

You are defining a literal Object with

// Object
var stuff = {};

You can define a literal Array like this

// Array
var stuff = [];

then

stuff.push(element);

---

Arrays actually get their bracket syntax stuff[index] inherited from their parent, the Object. This is why you are able to use it the way you are in your first example.

This is often used for effortless reflection for dynamically accessing properties

stuff = {}; // Object

stuff['prop'] = 'value'; // assign property of an 
                         // Object via bracket syntax

stuff.prop === stuff['prop']; // true

回答2:

so it's easy)))

Watch this...

    var stuff = {};
    $('input[type=checkbox]').each(function(i, e) {
        stuff[i] = e.checked;
    });

And you will have:

Object {0: true, 1: false, 2: false, 3: false}

Or:

$('input[type=checkbox]').each(function(i, e) {
    stuff['row'+i] = e.checked;
});

You will have:

Object {row0: true, row1: false, row2: false, row3: false}

Or:

$('input[type=checkbox]').each(function(i, e) {
    stuff[e.className+i] = e.checked;
});

You will have:

Object {checkbox0: true, checkbox1: false, checkbox2: false, checkbox3: false}

回答3:

stuff is an object and push is a method of an array. So you cannot use stuff.push(..).

Lets say you define stuff as an array stuff = []; then you can call push method on it.

This works because the object[key/value] is well formed.

stuff.push( {'name':$(this).attr('checked')} );

Whereas this will not work because the object is not well formed.

stuff.push( {$(this).attr('value'):$(this).attr('checked')} );

This works because we are treating stuff as an associative array and added values to it

stuff[$(this).attr('value')] = $(this).attr('checked');

回答4:

Another way of doing it would be:

stuff = Object.assign(stuff, {$(this).attr('value'):$(this).attr('checked')});

Read more here: Object.assign()

回答5:

This is really easy: Example

//my object
var sendData = {field1:value1, field2:value2};

//add element
sendData['field3'] = value3;