isNull
Checks if the given value is null.
This function tests whether the provided value is strictly equal to null
. It returns true
if the value is null
, and false
otherwise.
This function can also serve as a type predicate in TypeScript, narrowing the type of the argument to null
.
Signature
typescript
function isNull(x: unknown): x is null;
Parameters
x
(unknown
): The value to test if it is null.
Returns
(x is null
): True if the value is null, false otherwise.
Examples
typescript
const value1 = null;
const value2 = undefined;
const value3 = 42;
console.log(isNull(value1)); // true
console.log(isNull(value2)); // false
console.log(isNull(value3)); // false