Form an array from the for-loop

Question

I have a for loop in which I am getting all the values one by one but I need to form those values into one array.

Can any one let me know how to get form all the values into one array.

for (var i = 0; i < marray.length; i++) {
    mId = marray[i].id;
    var yourArray = [];
    yourArray.push(marray);
    console.log(marray);
}

Output getting from the above code is : ["0123"] and ["3456"]

But the expected output is ["0123","3456"]

each is like foreach() in php, i think it is maybe helpful for you — Mohammad Kermani, Jun 16 '14 at 09:03
You don't need to declare the array inside the loop. Declare it before the start of the loop. — Mahesh Bansod, Jun 16 '14 at 09:10
Thanks for the answer. It works fine, Is there any other method to reduce the code because I have two for loops, it just looping all the time, once the value is present the loop should break there itself. — user1853128, Jun 16 '14 at 09:36

score 6 · Accepted Answer · answered Jun 16 '14 at 09:01

6

You are creating a new yourArray for each loop iteration. Instead of doing that, create it just once before starting the loop:

var yourArray = [];
for (var i = 0; i < marray.length; i++) {
    mId = marray[i].id;
    yourArray.push(mId);
}

Note that I have changed the code to read yourArray.push(mId) because from the question it seems that's what you want -- not yourArray.push(marray).

A more compact way of doing the same is to use the array map function like this:

var yourArray = marray.map(function(row) { return row.id; });

This last version won't work out of the box in IE 8, so if you care about that you need to take appropriate measures.

answered Jun 16 '14 at 09:01

Jon

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I tried using .map but it is not working. could you please help me out – user1853128 Jun 16 '14 at 09:32
@user1853128: If it doesn't work for you then you are making some error. Please post a new question explaining what you did, what you expected and what happened instead. People who are available will answer. – Jon Jun 16 '14 at 09:39
Thank you jon, inorder to break the statement once the loop is done should I use return false or break. – user1853128 Jun 16 '14 at 09:43
@user1853128: What does "break the statement" mean? Again, I can't tell what you are asking exactly because there is only a very vague description. Please use the appropriate terminology and ask proper full questions when you are unsure about something. – Jon Jun 16 '14 at 09:45

score 0 · Answer 2 · answered Jun 16 '14 at 09:01

0

decalare variable in outside for loop..

  var yourArray = [];


     for (var i = 0; i < marray.length; i++) {
                    mId = marray[i].id;
                    yourArray.push(mid);

                }
 console.log(yourArray);

answered Jun 16 '14 at 09:01

Balachandran

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Sridhar R · Answer 3 · 2014-06-16T09:25:11.447

0

Initialise yourArray before the loop

Try this

var yourArray = [];
for (var i = 0; i < marray.length; i++) {
    mId = marray[i].id;
    yourArray.push(mId);
}

edited Jun 16 '14 at 09:25

answered Jun 16 '14 at 09:05

Sridhar R

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i didn't have downvoted, but using `for...in` for arrays isn't a good practice for sequential looping over arrays. You should use `for` in that situation. Please refer to [this](http://stackoverflow.com/a/500531/2412895) for answer. – KarelG Jun 16 '14 at 09:12
While this code block may answer the question, it would be best if you could provide a little explanation for why it does so. – PlasmaHH Jun 16 '14 at 09:23

score 0 · Answer 4 · edited Jun 16 '14 at 09:39

0

The var yourArray is initialized to null each time you enter the loop. Define it outside loop.

edited Jun 16 '14 at 09:39

Sudharsan S

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answered Jun 16 '14 at 09:07

Amrita

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Form an array from the for-loop

4 Answers4