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fixed incorrect function call
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Kevin Baker
Kevin Baker
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What is new() => T?

Essentially it is a way to declare an "Object Type" in which you can then create an instance of said "Object Type" with.

Example

class XMyClass { // ... } // Creates new object types that don't have arguments in their constructors function createObjectGivenObjectType<T>(ObjectType: new() => T): T { return new ObjectType(); } const objectXmyObject: XMyClass = createObjectcreateObjectGivenObjectType(XMyClass);

Simplify new() => T

I personally find it confusing when I see new() => T in a codebase. To simplify the problem, and to allow for better code readability, abstract this idea away from other devs by declaring a new type in your codebase called Type:

export type Type<T> = new (...args: any[]) => T;

Then the above createObjectGivenObjectType function can become:

// Then this reads as: ObjectType is a type of T function createObjectGivenObjectType<T>(ObjectType: Type<T>): T { return new ObjectType(); }

Furthermore, what does { new(): T; } mean? I know it must be a type, but how?

From the example you give it appears to be a more obtuse way of passing in an "Object Type" to a function.

Some examples that all do the same thing:

function create<T>(c: { new(): T; }): T { return new c(); } create(X); function create<T>(c: new() => T): T { return new c(); } create(X); function create<T>(c: Type<T>): T { return new c(); } create(X);

What is new() => T?

Essentially it is a way to declare an "Object Type" in which you can then create an instance of said "Object Type" with.

Example

class X { // ... } // Creates new object types that don't have arguments in their constructors function createObjectGivenObjectType<T>(ObjectType: new() => T): T { return new ObjectType(); } const objectX: X = createObject(X);

Simplify new() => T

I personally find it confusing when I see new() => T in a codebase. To simplify the problem, and to allow for better code readability, abstract this idea away from other devs by declaring a new type in your codebase called Type:

export type Type<T> = new (...args: any[]) => T;

Then the above createObjectGivenObjectType function can become:

// Then this reads as: ObjectType is a type of T function createObjectGivenObjectType<T>(ObjectType: Type<T>): T { return new ObjectType(); }

Furthermore, what does { new(): T; } mean? I know it must be a type, but how?

From the example you give it appears to be a more obtuse way of passing in an "Object Type" to a function.

Some examples that all do the same thing:

function create<T>(c: { new(): T; }): T { return new c(); } create(X); function create<T>(c: new() => T): T { return new c(); } create(X); function create<T>(c: Type<T>): T { return new c(); } create(X);

What is new() => T?

Essentially it is a way to declare an "Object Type" in which you can then create an instance of said "Object Type" with.

Example

class MyClass { // ... } // Creates new object types that don't have arguments in their constructors function createObjectGivenObjectType<T>(ObjectType: new() => T): T { return new ObjectType(); } const myObject: MyClass = createObjectGivenObjectType(MyClass);

Simplify new() => T

I personally find it confusing when I see new() => T in a codebase. To simplify the problem, and to allow for better code readability, abstract this idea away from other devs by declaring a new type in your codebase called Type:

export type Type<T> = new (...args: any[]) => T;

Then the above createObjectGivenObjectType function can become:

// Then this reads as: ObjectType is a type of T function createObjectGivenObjectType<T>(ObjectType: Type<T>): T { return new ObjectType(); }

Furthermore, what does { new(): T; } mean? I know it must be a type, but how?

From the example you give it appears to be a more obtuse way of passing in an "Object Type" to a function.

Some examples that all do the same thing:

function create<T>(c: { new(): T; }): T { return new c(); } create(X); function create<T>(c: new() => T): T { return new c(); } create(X); function create<T>(c: Type<T>): T { return new c(); } create(X);
Source Link
Kevin Baker
Kevin Baker
  • 629
  • 6
  • 8

What is new() => T?

Essentially it is a way to declare an "Object Type" in which you can then create an instance of said "Object Type" with.

Example

class X { // ... } // Creates new object types that don't have arguments in their constructors function createObjectGivenObjectType<T>(ObjectType: new() => T): T { return new ObjectType(); } const objectX: X = createObject(X);

Simplify new() => T

I personally find it confusing when I see new() => T in a codebase. To simplify the problem, and to allow for better code readability, abstract this idea away from other devs by declaring a new type in your codebase called Type:

export type Type<T> = new (...args: any[]) => T;

Then the above createObjectGivenObjectType function can become:

// Then this reads as: ObjectType is a type of T function createObjectGivenObjectType<T>(ObjectType: Type<T>): T { return new ObjectType(); }

Furthermore, what does { new(): T; } mean? I know it must be a type, but how?

From the example you give it appears to be a more obtuse way of passing in an "Object Type" to a function.

Some examples that all do the same thing:

function create<T>(c: { new(): T; }): T { return new c(); } create(X); function create<T>(c: new() => T): T { return new c(); } create(X); function create<T>(c: Type<T>): T { return new c(); } create(X);