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I want to declare a function in TypeScript that returns the type of the current instance's type, e.g. in a fluent API that returns this.
Is there a type variable for "this type"? (I would rather not use the ugly Java way of X<T extends X<T>>.)
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TypeScript treats a class as both value and type. This implicit type declared by TypeScript describes the shape of the instance a class produces. Therefore when a class is used as a type, such as using let value :Class annotation, TypeScript checks if the value has all the public properties of the Class .
Use the typeof operator to check the type of a variable in TypeScript, e.g. if (typeof myVar === 'string') {} . The typeof operator returns a string that indicates the type of the value and can be used as a type guard in TypeScript.
The type syntax for declaring a variable in TypeScript is to include a colon (:) after the variable name, followed by its type. Just as in JavaScript, we use the var keyword to declare a variable. Declare its type and value in one statement.
There is not a way to do this yet in TypeScript. See issue https://github.com/Microsoft/TypeScript/issues/285 for voting/discussion.
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