In JavaScript, passing an array as a function parameter is possible.

Problem

I’d want to use an array as parameters to invoke a function:

const x = ['p0', 'p1', 'p2'];
call_me(x[0], x[1], x[2]); // I don't like it

function call_me (param0, param1, param2 ) {
  // ...
}

Is there a more efficient way to pass the contents of x to call me()?

Asked by Robert

Solution #1

const args = ['p0', 'p1', 'p2'];
call_me.apply(this, args);

Function.prototype.apply is documented in MDN ().

You can use a spread argument instead if your environment supports ECMAScript 6:

call_me(...args);

Answered by KaptajnKold

Solution #2

Why don’t you provide the complete array to the method and process it as needed?

var x = [ 'p0', 'p1', 'p2' ]; 
call_me(x);

function call_me(params) {
  for (i=0; i<params.length; i++) {
    alert(params[i])
  }
}

Answered by Karl Johan

Solution #3

There is a new spread operator in the ES6 standard… that achieves exactly that.

call_me(...x)

Except for Internet Explorer, it is supported by all major browsers.

The spread operator can be used for a variety of additional purposes, as the attached material demonstrates.

Answered by BoltKey

Solution #4

You don’t expect this to be set because call me is a global function.

var x = ['p0', 'p1', 'p2'];
call_me.apply(null, x);

Answered by plexer

Solution #5

As @KaptajnKold had already stated,

var x = [ 'p0', 'p1', 'p2' ];
call_me.apply(this, x);

You also don’t have to define all of the parameters for the call me function. You can simply rely on arguments.

function call_me () {
    // arguments is a array consisting of params.
    // arguments[0] == 'p0',
    // arguments[1] == 'p1',
    // arguments[2] == 'p2'
}

Answered by 徐竟峰

Post is based on https://stackoverflow.com/questions/2856059/passing-an-array-as-a-function-parameter-in-javascript