Unpacking array into separate variables in JavaScript

user_84478 0
Viewed 96415

This is a simple problem, and I've done it before. I just can't remember how, or what exactly it was called.

In python I can do this:

arr = ['one', 'two']
one, two = arr

how do I do that in JavaScript?

arrays javascript
10 Answers

The destructuring assignment syntax is a JavaScript expression that makes it possible to unpack values from arrays, or properties from objects, into distinct variables.

Here is an example. You can try like this.

 let a, b, rest;
[a, b] = [10, 20];

console.log(a);
// expected output: 10

console.log(b);
// expected output: 20

[a, b, ...rest] = [10, 20, 30, 40, 50];

console.log(rest);
// expected output: Array [30,40,50]
user_27386950

My example works for your example but also if you dont know the array or the array length.

arr = ['one', 'two'];
var length = arr.length;
for (var i = 0; i < length; i++)
{
   var val = arr[i];
   eval('var '+arr[i]+'= arr[i];');
}

Know you have 2 variables. The first is 'one' who is "one"and the second is 'two' who is "two". Your problem is solved! But for the code snippet, i created extra elements to display the var's and i logged it.

arr = ['one', 'two'];
var length = arr.length;
for (var i = 0; i < length; i++)
{
   var val = arr[i];
   eval('var '+arr[i]+'= arr[i];');
}
var p = document.createElement("p");
p.innerHTML = one + " " + two;
document.body.appendChild(p);
console.log(one, two);

user_155370890 
arr = ['one', 'two'];
var length = arr.length;
for (var i = 0; i < length; i++)
{
   var val = arr[i];
   eval('var '+arr[i]+'= arr[i];');
}
var p = document.createElement("p");
p.innerHTML = one + " " + two;
document.body.appendChild(p);
console.log(one, two);
user_189445310
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