SyntaxError: getter functions must have no arguments

The JavaScript exception "getter functions must have no arguments" occurs when a getter is declared and the parameter list is non-empty.

Message

SyntaxError: Getter must not have any formal parameters. (V8-based)
SyntaxError: getter functions must have no arguments (Firefox)
SyntaxError: Unexpected identifier 'x'. getter functions must have no parameters. (Safari)

Error type

SyntaxError

What went wrong?

The get property syntax looks like a function, but it is stricter and not all function syntax is allowed. A getter is always invoked with no arguments, so defining it with any parameter is likely an error.

Note that this error only applies to property getters using the get syntax. If you define the getter using Object.defineProperty(), etc., the getter is defined as a normal function, although it's likely still an error if the getter expects any arguments, as it will be called without any.

Examples

Invalid cases

js
const obj = {
  get value(type) {
    return type === "string" ? String(Math.random()) : Math.random();
  },
};

Valid cases

js
// Remove the parameter
const obj = {
  get value() {
    return Math.random();
  },
};

// Use a normal method, if you need a parameter
const obj = {
  getValue(type) {
    return type === "string" ? String(Math.random()) : Math.random();
  },
};

See also