CODEWITHSUNDEEP
javascript
zerkms
zerkms

Reputation: 254906

How to get a slice from "arguments"

All you know that arguments is a special object that holds all the arguments passed to the function.

And as long as it is not an array - you cannot use something like arguments.slice(1).

So the question - how to slice everything but first element from arguments?

UPD:

seems like there is no way without converting it to an array with

var args = Array.prototype.slice.call(arguments);

If someone posts another solution it would be great, if not - I'll check the first one with the line above as an answer.

Upvotes: 85

Views: 44961

Answers (9)

AamirR
AamirR

Reputation: 12198

Arguments type is iterable, so using the ES6 (ES2015) spread ... operator, then use Array.slice([start], [end]) method, such as

function omitFirstAndLastArgument(value) {
  const args = arguments.length > 2 ? [...arguments].slice(1, -1) : [];
  return args;
}

omitFirstAndLastArgument(1, 2, 3, 4, 5, 6); //  [2, 3, 4, 5]

Upvotes: 0

OpportunisticHype
OpportunisticHype

Reputation: 1

you can use this too

function arg(myArr) {
  let arg = Object.values(arguments).slice(2, 4);
  console.log(arg);
  return arg;
};

arg([1, 2, 3], 4, [5,6], 7)

see here for reference: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/values

...

Upvotes: 0

Umur Karagöz
Umur Karagöz

Reputation: 3190

Meddling with array functions is not actually necessary.

Using rest parameter syntax ...rest is cleaner and more convenient.

Example

function argumentTest(first, ...rest) {
  console.log("First arg:" + first);

  // loop through the rest of the parameters
  for (let arg of rest) {
    console.log("- " + arg);
  }
}

// call your function with any number of arguments
argumentTest("first arg", "#2", "more arguments", "this is not an argument but a contradiction");

...Rest

Upvotes: 29

ntarlapan
ntarlapan

Reputation: 391

You can use ...rest within the function to separate the first and the rest of the arguments:

function foo(arr) {
  const [first, ...rest] = arguments;
  console.log(`first = ${first}`);
  console.log(`rest = ${rest}`);
}
//Then calling the function with 3 arguments:
foo(1,2,3)

Upvotes: 0

Thierryk
Thierryk

Reputation: 1

You can use the method [].slice.call(arguments, 1)

[].slice will return you the slice function object and you can call it as the arguments and 1 are the parameters

Upvotes: 0

Di Tran
Di Tran

Reputation: 203

This can be a way: 

var args = Array.from(arguments).slice(1);

Upvotes: 12

bluescrubbie
bluescrubbie

Reputation: 540

From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/arguments:

You should not slice on arguments because it prevents optimizations in JavaScript engines (V8 for example). Instead, try constructing a new array by iterating through the arguments object.

So Paul Rosiana's answer above is correct

Upvotes: 13

Tess Rosania
Tess Rosania

Reputation: 10103

You can "slice without slicing" by procedurally walking the arguments object:

function fun() {
  var args = [];

  for (var i = 1; i < arguments.length; i++) {
    args.push(arguments[i]);
  }

  return args;
}

fun(1, 2, 3, 4, 5); //=> [2, 3, 4, 5]

Upvotes: 11

nnnnnn
nnnnnn

Reputation: 150030

Q. How to slice everything but first element from arguments?

The following will return an array containing all arguments except the first:

var slicedArgs = Array.prototype.slice.call(arguments, 1);

You don't have to convert arguments to an array first, do it all in one step.

Upvotes: 140

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