requireNumberLike
function requireNumberLike(
value: unknown,
message: string = "Expected a numeric value."
): number | string;
A finite number, or a string that converts to one. NaN, the infinities and the empty string are excluded, which is what separates this from a bare Number(value).
isX and nonX answer a question and never interrupt control flow; requireX and requireNonX hand the value back or throw. The scheme is explained in Validation conventions.
Parameters
Parameter | Type | Description |
|---|---|---|
|
| The value to validate. |
|
| The message of the exception. A default is used when omitted. |
Returns
number | string — the same value, typed as a numeric value.
Throws
Exception | Condition |
|---|---|
| the value is not convertible to a number. |
Examples
What passes and what does not
requireNumberLike(1); // => 1
requireNumberLike("1.5"); // => "1.5"
requireNumberLike(NaN); // throws IllegalArgumentException
requireNumberLike(Infinity); // throws IllegalArgumentException
See also
Source
23 September 2026
This documentation was generated with AI (Claude) from the library's source code.