Can you explain what comes after the equal sign in a TypeScript object?

While browsing through this response on stackoverflow

The author answered: // How I usually initialize

var foo:IFoo = <any>{};

I attempted to research it online, but unfortunately, I couldn't find any information about it. Could someone explain what the section <any>{}; means?

Also, is {} as any equivalent to <any>{}?

Answer №1

Can {} as any be considered equivalent to <any>{}?

Absolutely, the old syntax is <any>. For more information, refer to Type assertions

But what exactly does this mean?

To understand better, check out the details on Type assertions:

There are times when you may have more knowledge about a value than TypeScript does. This typically occurs when you have a deeper understanding of an entity's type compared to its current type.

Type assertions serve as a way to inform the compiler that you know what you're doing. It functions similar to type casts in other programming languages, but without any special data validation or restructuring. Type assertions do not impact runtime and are only utilized by the compiler. TypeScript assumes that you, as the programmer, have implemented any necessary checks.

There are two forms of type assertions: one using angle brackets and the other using the 'as' syntax.

The use of any in such cases helps ensure successful compilation:

interface IFoo{
  someProp: string
}

var foo:IFoo = <any>{};

This prevents issues like missing properties, which would result in an error:

var foo:IFoo = {}

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