SyntaxError: missing variable name

The JavaScript exception "missing variable name" is a common error. It is usually caused by omitting a variable name or a typographic error.

Message#

SyntaxError: missing variable name (Firefox)
SyntaxError: Unexpected token '='. Expected a parameter pattern or a ')' in parameter list. (Safari)

Error type#

{{jsxref("SyntaxError")}}

What went wrong?#

A variable is missing a name. The cause is most likely a typo or a forgotten variable name. Make sure that you've provided the name of the variable before the = sign.

When declaring multiple variables at the same time, make sure that the previous lines/declaration does not end with a comma instead of a semicolon.

Examples#

Missing a variable name#

```js-nolint example-bad const = "foo";

It is easy to forget to assign a name for your variable!

```js example-good
const description = "foo";

Reserved keywords can't be variable names#

There are a few variable names that are reserved keywords. You can't use these. Sorry :(

```js-nolint example-bad const debugger = "whoop"; // SyntaxError: missing variable name

### Declaring multiple variables

Pay special attention to commas when declaring multiple variables.
Is there an excess comma, or did you use commas instead of semicolons?
Did you remember to assign values for all your `const` variables?

```js-nolint example-bad
let x, y = "foo",
const z, = "foo"

const first = document.getElementById("one"),
const second = document.getElementById("two"),

// SyntaxError: missing variable name

The fixed version:

```js example-good let x, y = "foo"; const z = "foo";

const first = document.getElementById("one"); const second = document.getElementById("two");

### Arrays

{{jsxref("Array")}} literals in JavaScript need square brackets around the values.
This won't work:

```js-nolint example-bad
const arr = 1,2,3,4,5;
// SyntaxError: missing variable name

This would be correct:

js example-good const arr = [1, 2, 3, 4, 5];

See also#

• Lexical grammar
• {{jsxref("Statements/var", "var")}}
• Grammar and types guide