Create Duplicate Objects Into Array Based On Length Provided

I want to insert duplicate values into array based on length provided like this: var a = [{displayName: 'bar'}, {displayName:'google'}, {displayName:'mod'}];; var dataTypesLength=

Solution 1:

Just loop the array of objects and use fill to get your result.

var a = [{displayName: 'bar'}, {displayName:'google'}, {displayName:'mod'}];
var dataTypesLength= 4;
var arr=[];
function fillArray(value, len) {
  return Array(len).fill(value);
}
for (var i=0; i<a.length; i++){
  var b = fillArray(a[i],dataTypesLength);
  arr.push(...b);
}
console.log(arr);

Solution 2:

You can use this (single line solution):

a.reduce((acc,x)=>{ acc.push(...new Array(dataTypesLength).fill(x)); return acc;}, [])

Explaination :

• Reducing the input array starting from empty array []
• For every element creating a new array with length dataTypesLength and filling all the new array with the current element new Array(dataTypesLength).fill(x)
• Spread the new created array and push it into accumulator array acc.push(...new Array(dataTypesLength).fill(x))
• Return the accumulator array

Solution 3:

You can use map with Object.assign so that each object will have independent reference

var a = [{displayName: 'bar'}, {displayName:'google'}, {displayName:'mod'}];
var dataTypesLength= 4;

a= a.map(obj => { return Array(dataTypesLength).fill(null).map( e => Object.assign({}, obj)) }).flat();
console.log(a)

Solution 4:

you can try reduce

var a = [{displayName: 'bar'}, {displayName:'google'}, {displayName:'mod'}];;
var dataTypesLength= 4;

a  = a.reduce(
(f,obj ) => {
var dup = new Array(dataTypesLength); 
f.push(...dup.fill(obj));
return f;
}, [] )