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isNull()

isNull(value): value is null

Checks if a value is null.

remarque

Only checks null, not undefined. Use isNil to check both.

Parameters​

value: unknown​

The value to check.

Returns: value is null​

true if the value is null, false otherwise.

See Also​

Since​

1.0.0

Example​

isNull(null);      // => true
isNull(undefined); // => false
isNull(0);         // => false
isNull('');        // => false

How it works?​

Type guard that checks if a value is null.

Type Narrowing​

Common Checks​

ValueResult
null true
undefined false
0 false
'' false
false false

vs isNil​

Use Cases​

Detect explicit absence 📌​

Check strictly for null values. Essential for differentiating between "no value" (null) and "not set" (undefined).

if (isNull(record.deletedAt)) {
  // Record is active (deletedAt is explicitly null)
}