Javascript remove keys from nested arrays

Question

I am retrieving data from mysql and want to save each row of data in localStorage as array. The following is my nested array received at javascript end.

arr = [{image_id: "80", imagename: "Image1",firstx: "267", firsty: "403"}, 
      {image_id: "80", imagename: "Image1",firstx: "320", firsty: "470"}, 
      {image_id: "80", imagename: "Image2",firstx: "126", firsty: "237"}
       ]

From this I want to remove the image_id, imagename, firstx and firsty and return a result that is an array and contains only the values of each array. The desired output is

newarr =[[80,Image1,267,403],[80,Image1,320,470],[80,Image2,126,237]]

I have done the following:

var newarr = [];
for (var i = 0, l = arr.length; i < l; i++) {
    var keys = Object.keys(arr[i]);
    for (var j = 0, k = keys.length; j < k; j++) {
        newarr.push(arr[i][keys[j]]);
        }
}

console.log(newarr)

This returns each element of as an array. The resultant array will be pushed to localStorage as a nested array.

CertainPerformance · Accepted Answer · 2018-08-03 07:10:06Z

5

I'm guessing you want an array and not an object - map by Object.values:

const arr = [{image_id: "80", imagename: "Image1",firstx: "267", firsty: "403"}, 
  {image_id: "80", imagename: "Image1",firstx: "320", firsty: "470"}, 
  {image_id: "80", imagename: "Image2",firstx: "126", firsty: "237"}
];
console.log(arr.map(Object.values));

answered Aug 3, 2018 at 7:10

CertainPerformance

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Comments

Mahesh Kumar · Accepted Answer · 2018-08-03 07:25:17Z

0

var newarr = [];
for (var i = 0, l = arr.length; i < l; i++) {
    var keys = Object.keys(arr[i]);
    newarr[i] = [];
    for (var j = 0, k = keys.length; j < k; j++) {
        newarr[i].push(arr[i][keys[j]]);
        }
}

answered Aug 3, 2018 at 7:25

Mahesh Kumar

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1 Comment

Mahesh Kumar Over a year ago

It can be done by just adding newarr[i] = []; in your code and pushing every j in newarr[i].

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