How to break an array after certain limit in Javascript

Question

Following is my array that I need to break in parts, i.e to break into parts of 2 as shown below -

Array to iterate -

[
    {elem: 1},
    {elem: 2},
    {elem: 3},
    {elem: 4},
    {elem: 5},
    {elem: 6},
    {elem: 7},
    {elem: 8},
    {elem: 9}
]

Desired Output -

[
 {week1: [{elem: 1},{elem: 2}]},
 {week2: [{elem: 3},{elem: 4}]},
 {week3: [{elem: 5},{elem: 6}]},
 {week4: [{elem: 7},{elem: 8}]},
 {week5: [{elem: 9}]},
]

Following is the code I am trying but somehow breaking, let me know what I am doing wrong here -

My Code -

var myArr = [
    {elem: 1},
    {elem: 2},
    {elem: 3},
    {elem: 4},
    {elem: 5},
    {elem: 6},
    {elem: 7},
    {elem: 8},
    {elem: 9}
];

var arrayBreakNum = 2;
var newArr = [];
var weekNum = 1;

for(var i=1; i<= myArr.length; i++) {
    newArr.['week'+weekNum].push(myArr[i]);
    if(i%2 == 0)
        weekNum = weekNum + 1;
}

console.log(newArr);

Philipp Sander · Accepted Answer · 2015-11-26 14:47:01Z

3

There are a few things you need to change:

Theres a syntax error here:

newArr.['week'+weekNum].push(myArr[i]);

Change to:

newArr['week'+weekNum].push(myArr[i]);

You're trying to push to an array you haven't yet initialised here:

newArr.['week'+weekNum].push(myArr[i]);

Change to:

newArr['week'+weekNum] = [];
for(var i=1; i<= myArr.length; i++) {
    newArr['week'+weekNum].push(myArr[i]);
    if(i%2 == 0){
        weekNum = weekNum + 1;
        newArr['week'+weekNum] = [];
    }
}

Working Example: http://jsfiddle.net/6e6d3fuv/

edited Nov 26, 2015 at 14:47

Philipp Sander

10.3k7 gold badges49 silver badges80 bronze badges

answered Nov 26, 2015 at 14:45

Curtis

104k69 gold badges280 silver badges359 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

lordkain Over a year ago

almost working, you have element 1 in 5the array and not in first

Curtis Over a year ago

@lordkain So does the OP :)

Philipp Sander · Accepted Answer · 2015-11-26 14:52:19Z

1

var myArr = [
    {elem: 1},
    {elem: 2},
    {elem: 3},
    {elem: 4},
    {elem: 5},
    {elem: 6},
    {elem: 7},
    {elem: 8},
    {elem: 9}
];

var arrayBreakNum = 2;
var newArr = [];
var weekNum = 1;

for(var i=1; i<= myArr.length; i++) {
    //you need to create an empty array
    if(!newArr['week'+weekNum]) {
        newArr['week'+weekNum] = [];
    }

    newArr['week'+weekNum].push(myArr[i]); //you had an unessecary . in this line
    if(i%2 == 0) {
        weekNum = weekNum + 1;
    }
}

console.log(newArr);

edited Nov 26, 2015 at 14:52

answered Nov 26, 2015 at 14:45

Philipp Sander

10.3k7 gold badges49 silver badges80 bronze badges

1 Comment

Tech Solvr Over a year ago

Thanks and +1 for the solution

Collectives™ on Stack Overflow

How to break an array after certain limit in Javascript

2 Answers 2

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related