The any
type in Typescript serves as a workaround when there is no clear way to specify what you are doing, allowing you to bypass type checking temporarily.
It's important to note that types may not default to any
if type annotations are omitted. Typescript will often infer a type and enforce it. For example, declaring let x = 2;
will automatically infer the type of x
as number
, leading to an error if you later assign x = "cat";
.
In certain scenarios where explicit typing is necessary, such as with generic types, using any
becomes essential:
type Pair<A, B> = [A, B];
declare function needsSomethingPairedWithString(value: Pair<any, string>): void;
When defining functions like needsSomethingPairedWithString
, specifying only the required type while leaving room for flexibility can be achieved by using Pair<any, string>
.
While unknown
is preferable to any
for cases where information is both unknown and irrelevant, any
remains appropriate for handling constraints effectively.
Consider enabling the --noImplicitAny
flag in the compiler settings to identify instances where any
is inferred and potentially lead to errors. This practice encourages explicit declaration of any
, promoting code readability and safety across projects implementing Typescript from the start.