TypeError: "x" has no properties - JavaScript 编辑

The JavaScript exception "null (or undefined) has no properties" occurs when you attempt to access properties of null and undefined. They don't have any.

Message

TypeError: Unable to get property {x} of undefined or null reference (Edge)
TypeError: null has no properties (Firefox)
TypeError: undefined has no properties (Firefox)

Error type

TypeError.

What went wrong?

Both, null and undefined, have no properties you could access.

Examples

null and undefined have no properties

null.foo;
// TypeError: null has no properties

undefined.bar;
// TypeError: undefined has no properties

See also

• null
• undefined