Question

I have 3 arrays like:

var arr1 = [];
var arr2 = [];
var arr3 = [];

//When I want to add something into array then I use
arr1.push("text");
arr2.push("text");

but is it possible to make something like the following example?

//example:
var arr = [];

arr['group1'].push("text1");
arr['group2'].push("text2");
arr['group2'].push("textn");

//and then iterate like:

for(item in arr['group1'])
  console.log(item);

is it even possible to do something like that? I have tried but does not work.

Answer 1

There’s a fundamental misunderstanding though, arr is an array but you’re using it as an associative array, which in JavaScript is better represented with an object {}. for...in is for objects, NOT arrays, the MDN has a warning note about it:

for..in should not be used to iterate over an Array where index order
is important…

I would advice even if index is trivial to use a regular for loop or a forEach.

Consider using the following, more appropiate approach.

var obj = {
  group1: ['text1'],
  group2: ['text2'],
  group3: ['text3']
};

// pushing more strings
obj.group1.push('foo');
obj['group2'].push('baz');