JavaScript isError() Method
Description
The Error.isError() method returns true
if a passed value is an Error.
Otherwise it returns false.
All these returns false.
- Error.isError(5);
- Error.isError(-5);
- Error.isError("Hello");
- Error.isError("Error");
- Error.isError({});
- Error.isError([]);
- Error.isError(true);
- Error.isError(false);
- Error.isError();
- Error.isError(null);
- Error.isError(undefined);
Syntax
Error.isError(value)
Parameters
| Parameter | Description |
| value | Optional. A value. |
Return Value
| Type | Description |
| Boolean | trueif the value is an Error.Otherwise false.
|
See Also:
Browser Support
Error.isError() is a proposal for JavaScript 2026.
Since it has reached Stage 4, we can expect it to be part of an upcoming ECMAScript 2026 edition.