"any" in Typescript

Question

I am beginner in typescript. I have a doubt in usage of "any" type.

Using "any" is basically opting out type checking if I am right. For example

1. var num:any = 12

2. var num = 12

we could probably use the second one itself, what's the need for 'any'?

Answer 1

While the two are equivalent in use (because any is the default type when unspecified) by explicitly specifying the type as any, you explicitly declare the intent.

Intellisense, where available, will display the type as any, allowing easier understanding how your variable is meant to be used.

Answer 2

First of all - If we speak about Typescript, lets avoid the var key-word.

We may need to describe the type of variables that we do not know when we are writing an application. These values may come from dynamic content, e.g. from the user or a 3rd party library. In these cases, we want to opt-out of type-checking and let the values pass through compile-time checks. To do so, we label these with the any type:

Example to this:

let notSure: any = 4;
notSure = "maybe a string instead";
notSure = false; // okay, definitely a boolean

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