How to combine an array in javascript

Question

Hello I want to merge a array based on the unique item in the array.

The object that I have

totalCells = []

In this totalCells array I have several objects like this

totalCells = [
 {
 cellwidth: 15.552999999999999,
 lineNumber: 1
 }, 
 {
 cellwidth: 14,
 lineNumber: 2
 },
 {
 cellwidth: 14.552999999999999,
 lineNumber: 2
 }, 
 {
 cellwidth: 14,
 lineNumber: 1
 }
];

Now I want to make a array where I have combination of array based on the lineNumber.

Like I have a object with lineNumber property and cellWidth collection. Can I do this ?

I can loop through each row and check if the line number is same and then push that cellwidth. Is there any way that I can figure ?

I'm trying to get an output like this.

totalCells = [
{
 lineNumber : 1,
 cells : [15,16,14]
},
{
 lineNumber : 2,
 cells : [17,18,14]
}
]

• Dipak Kumar Pusti: w3schools.com/jsref/jsref_concat_array.asp
• Moiz: I want to concat based on the lineNumber
• Barmar: can you show what result you're trying to get?
• Barmar: Your objects are not valid. Objects are enclosed in { ... }, [...] is only for arrays.
• Moiz: This is a array with sub object with array

Answer 1

var newCells = [];
for (var i = 0; i < totalCells.length; i++) {
 var lineNumber = totalCells[i].lineNumber;
 if (!newCells[lineNumber]) { // Add new object to result
 newCells[lineNumber] = {
 lineNumber: lineNumber,
 cellWidth: []
 };
 }
 // Add this cellWidth to object
 newcells[lineNumber].cellWidth.push(totalCells[i].cellWidth);
}

Answer 2

What about something like this :

totalCells.reduce(function(a, b) {
 if(!a[b.lineNumber]){
 a[b.lineNumber] = {
 lineNumber: b.lineNumber,
 cells: [b.cellwidth]
 }
 }
 else{
 a[b.lineNumber].cells.push(b.cellwidth);
 }
 return a;
}, []);

Hope this helps!

Answer 3

Do you mean something like this?

var cells = [
{
 cellwidth: 15.552999999999999,
 lineNumber: 1
}, 
{
 cellwidth: 14,
 lineNumber: 2
},
{
 cellwidth: 14.552999999999999,
 lineNumber: 2
}, 
{
 cellwidth: 14,
 lineNumber: 1
}
]
var totalCells = [];
for (var i = 0; i < cells.length; i++) {
 var cell = cells[i];
 if (!totalCells[cell.lineNumber]) {
 // Add object to total cells
 totalCells[cell.lineNumber] = {
 lineNumber: cell.lineNumber,
 cellWidth: []
 }
 }
 // Add cell width to array
 totalCells[cell.lineNumber].cellWidth.push(cell.cellwidth);
}