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