The JavaScriptstrict mode-only exception "'arguments' can't be defined or assigned to in strict mode code" or "'eval' can't be defined or assigned to in strict mode code" occurs when attempting to create abinding calledarguments oreval, or assign to such a name.

Message

SyntaxError: Unexpected eval or arguments in strict mode (V8-based)SyntaxError: 'arguments' can't be defined or assigned to in strict mode code (Firefox)SyntaxError: Cannot modify 'arguments' in strict mode. (Safari)SyntaxError: Cannot destructure to a parameter name 'arguments' in strict mode. (Safari)SyntaxError: Cannot declare a variable named arguments in strict mode. (Safari)SyntaxError: Cannot declare a catch variable named 'arguments' in strict mode. (Safari)SyntaxError: 'arguments' is not a valid function name in strict mode. (Safari)

Error type

What went wrong?

In strict mode, the namesarguments andeval behave as if they arereserved words: you cannot make they refer to anything other than thearguments object in functions or the globaleval function.

Examples

Invalid cases

"use strict";const arguments = [1, 2, 3];console.log(Math.max(...arguments));function foo(...arguments) {  console.log(arguments);}

Valid cases

"use strict";const args = [1, 2, 3];console.log(Math.max(...args));function foo(...args) {  console.log(args);}

See also

• Strict mode
• arguments
• eval()