To easily make every property on a type alias
or interface
to optional properties, you can use the Partial
utility type and pass the type alias
or interface
as the first type argument to it using the angled brackets symbol (<>
).
TL;DR
// a simple type
type Person = {
name: string;
age: number;
};
// make all the properties in the
// `Person` type to be optional
type OptionalPerson = Partial<Person>;
// contents of the `OptionalPerson` type
/*
{
name?: string | undefined;
age?: number | undefined;
}
*/
For example, let's say we have a type called Person
with 2 properties called name
having the type of string
and age
having the type of number like this,
// a simple type
type Person = {
name: string;
age: number;
};
Now to make all the properties in the Person
type to be optional we can use the Partial
utility type and pass the Person
interface as the first type argument to it using the angled brackets symbol (<>
).
It can be done like this,
// a simple type
type Person = {
name: string;
age: number;
};
// make all the properties in the
// `Person` type to be optional
type OptionalPerson = Partial<Person>;
// contents of the `OptionalPerson` type
/*
{
name?: string | undefined;
age?: number | undefined;
}
*/
Now if you hover over the OptionalPerson
type you can see that all the properties are now optional which is what we want to happen.
See the above code live in codesandbox.
That's all 😃!