Please note, this is a STATIC archive of website developer.mozilla.org from 03 Nov 2016, cach3.com does not collect or store any user information, there is no "phishing" involved.

ReferenceError: deprecated caller or arguments usage

I volontari di MDN non hanno ancora tradotto questo articolo in Italiano. Registrati per tradurlo tu.

Message

Warning: ReferenceError: deprecated caller usage (Firefox)
Warning: ReferenceError: deprecated arguments usage (Firefox)
TypeError: 'callee' and 'caller' cannot be accessed in strict mode. (Safari)

Error type

A strict-mode-only warning that a ReferenceError occurred. JavaScript execution won't be halted.

What went wrong?

In strict mode, the Function.caller or Function.arguments properties are used and shouldn't be. They are deprecated, because they leak the function caller, are non-standard, hard to optimize and potentially a performance-harmful feature.

Examples

Deprecated function.caller or arguments.callee.caller

Function.caller and arguments.callee.caller are deprecated (see the reference articles for more information).

"use strict";

function myFunc() {
  if (myFunc.caller == null) {
    return 'The function was called from the top!';
  } else {
    return 'This function\'s caller was ' + myFunc.caller;
  }
}

myFunc();
// Warning: ReferenceError: deprecated caller usage
// "The function was called from the top!"

Function.arguments

Function.arguments is deprecated (see the reference article for more information).

"use strict";

function f(n) { g(n - 1); }

function g(n) {
  console.log('before: ' + g.arguments[0]);
  if (n > 0) { f(n); }
  console.log('after: ' + g.arguments[0]);
}

f(2);

console.log('returned: ' + g.arguments);
// Warning: ReferenceError: deprecated arguments usage

See also

Tag del documento e collaboratori

 Hanno collaborato alla realizzazione di questa pagina: fscholz
 Ultima modifica di: fscholz,