SyntaxError: 'arguments'/'eval' can't be defined or assigned to in strict mode code
The JavaScript strict 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 a binding called arguments
or eval
, 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 names arguments
and eval
behave as if they are reserved words: you cannot make they refer to anything other than the arguments
object in functions or the global eval
function.
Examples
Invalid cases
js
"use strict";
const arguments = [1, 2, 3];
console.log(Math.max(...arguments));
function foo(...arguments) {
console.log(arguments);
}
Valid cases
js
"use strict";
const args = [1, 2, 3];
console.log(Math.max(...args));
function foo(...args) {
console.log(args);
}