CODEWITHSUNDEEP
javascriptarrays
gk103
gk103

Reputation: 377

Pushing data into an array within a 2d array at specific index

var arr = []; //is a multidimensional array. 
var barr = []; //is a temp array that is dynamically updated
var key = "key1"

arr.push(key, barr);

arr now looks like this -> [key, Array(1)]

New data comes into barr how to i push another item into the nested array for the same key?

expected output should be something like this: [key, Array(2)]

Upvotes: 0

Views: 1636

Answers (2)

Dekel
Dekel

Reputation: 62566

Option #1:

You can push into the barr array:

var arr = []; //is a multidimensional array. 
var barr = []; //is a temp array that is dynamically updated
var key = "key1"

arr.push(key, barr);
console.log(arr);

barr.push('key2', 'key3');
console.log(arr);

barr is a reference to the array, and when you pushed it into your arra array you actually put there the reference, so when updating barr your reference is still there (and updated).

Option #2:

You can push into the array that is in the 2nd place of your array:

var arr = []; //is a multidimensional array. 
var barr = []; //is a temp array that is dynamically updated
var key = "key1"

arr.push(key, barr);
console.log(arr);

arr[1].push('key2', 'key3');
console.log(arr);

Upvotes: 2

Björn Tantau
Björn Tantau

Reputation: 1614

The way you did it the "key" is actually just another value in the array (at index 0). If you want to use a string as the key you'll have to use an object. You can set and get properties using the bracket syntax. The bracket syntax works with arrays as well, but only using integers as keys. 

var obj = {};
var barr = [];
var key = "key1";
obj[key] = barr;
// barr changed
obj[key] = barr;

Upvotes: 0

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