Array push function?

JavaScript
1

whats wrong in this code why i am getting push is not a function?

var name = ['Brinth','Green','Yellow'];

var newname = name;

  newname.push('Black');
     console.log(name);
2

This is because if you declare variables in the global scope with var, they are implicitly set as properties on the window object; and window already has a name property, and any assignment of which will get coerced to a string (which doesn’t have a .push() method):

var name = ['Brinth', 'Green', 'Yellow']

console.log(window.name) // String "Brinth,Green,Yellow"

This is indeed rather unfortunate, but then again it is also the reason why you can directly call say console.log(), where it should technically be window.console.log() (or window.setTimeout() etc.). Now there are ways around this; you can create a dedicated scope in an IIFE:

(function () {
  var name = ['Brinth', 'Green', 'Yellow']
  var newname = name

  newname.push('Black')
  console.log(name)
}())

or you can use const insteed of var, which does not assign to the global object:

const name = ['Brinth', 'Green', 'Yellow']
const newname = name

newname.push('Black')
console.log(name)
3 Likes
3

wow thats really unfortunate…

4

A better name for that array is names anyhow, or colors, instead of name.

Have you any problem with renaming the variables so that they work and make better sense? That’s a standard code improvement technique too.

2 Likes
5

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