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Errors: No properties

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

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/No_properties