isUndefined

isUndefined(a): a is undefined

Checks if x is undefined.

Example

isUndefined(undefined)
// => true

isUndefined(true)
// => false

isUndefined("1234")
// => false

isUndefined(null)
// => false

Alternatives

• Lodash isUndefined

Parameters

a

unknown

Returns

a is undefined

true if x is a undefined, false otherwise.