Function isDefined

isDefined<T>(x: T): x is NonNullable<T>
Alias for isNonNullish.

Checks if a value is "defined" (i.e., not null and not undefined). This is a type guard that narrows the type away from null and undefined.
Type Parameters
- T
  The type of the input value.
Parameters
- x: T
  The value to check.
Returns x is NonNullable<T>
true if the value is not null and not undefined, false otherwise.
Remarks
This function is different from isEnvDefined. isEnvDefined checks if an environment variable is defined and has a non-empty string value.
Example
```
let myValue: string | null = "hello";
if (isDefined(myValue)) {
  // myValue is now typed as string
}
```
Since
1.0
- Defined in builtins/primitive.ts:532