How to push an array inside another array element as a new property in JavaScript?

Question

So, For instance, I have the following array

var sections = [{ name: 'apple', count: 20 },
                 { name: 'banana', count: 80 },
                 { name: 'oranges', count: 10 }]

Now, if I want to add more items, then I can do

sections.push({ name: 'mango', count: '32' });

which will add the new array to sections.

Now, suppose, I have another array that shows where the fruit came from and how many.

var country = [{ country: 'usa', count: 5 },
               { country: 'brazil', count: 27 }]

So, I want to add this new country array to the third element of sections with a new prop called country as the following.

var sections = [{ name: 'apple', count: 20 },
                { name: 'banana', count: 80 },
                { name: 'oranges', count: 10,
                  country: [{ country: 'usa', count: 5 },
                            { country: 'brazil', count: 27 }]
                }]

How can I do this? I tried push, splice but couldn't figure it out at all.

I also tried sections[3].push.apply(country).. and many other things that I can't recall anymore. Either I received an error or just didn't push the array as I wanted to.

Really??!!!!. It's that easy? And I was trying all the other difficult ways in the world?? Gosh!!! Thanks — user1828605, Nov 09 '15 at 22:32
Does "another array" index positions correspond to `sections` array index positions ? — guest271314, Nov 09 '15 at 22:37
Not exactly sure what you mean, but the answers I got are all correct answers. — user1828605, Nov 09 '15 at 22:39
@user1828605 Yes . `sections` contains 3 items . Does "another array" contain 3 items corresponding to `section` items ? — guest271314, Nov 09 '15 at 22:43
It doesn't have to. The array that I'm working on has 18 items, and each item contains at least 3 items. However, based on the name, it dynamically adds "another array" which could be 1 or 1000 as long as the count of each item is greater than 100. — user1828605, Nov 09 '15 at 22:46

score 3 · Accepted Answer · answered Nov 09 '15 at 22:30

You could try something like this:

sections[2].country =  country;

Here, writing sections[2] we peek a reference to the third item of the sections. Then we define a property called country and we assign to it the value we want.

Why push didn't work?

The push is an array method, that gives you the ability to push an element at the end of an array. If you try to make use of push on sections[2] will not work, since sections[2] is not an array. The same holds for the splice, it's an array method.

score 1 · Answer 2 · answered Nov 09 '15 at 22:31

push is for adding to an array, not for adding properties to an object. For a property, just assign the property name.

sections[2].country = country;

If the property already existed and you wanted to add to it, you would use push as follows:

section[2].country.push({country: 'venezuela', count: 20});

And don't forget that array indexes start at 0, so the third element is [2].

How to push an array inside another array element as a new property in JavaScript?

2 Answers2