How to useInference with Tuple Parameter in Javascript
This approach utilizes TypeScriptâs type inference capabilities to deduce the return type from a tuple parameter directly within the function signature. By leveraging the types of the tuple parameters, TypeScript infers the appropriate return type, enhancing code readability and reducing the need for explicit type annotations.
Example: We define a function, extractReturnType, which takes a tuple parameter and returns the last element of the tuple. The return type is directly inferred by TypeScript based on the tuple parameter provided.
function extractReturnType<T extends any[]>(...args: T): T[number] {
return args[args.length - 1];
}
// Usage
const result1: string | number | boolean = extractReturnType("Hello", 42, true);
const result2: number = extractReturnType(1, 2, 3, 4);
console.log(result1);
console.log(result2);
Output:
true
4
How to Infer Return Type from a Tuple Parameter ?
In TypeScript, inferring the return type from a tuple parameter involves deriving the type of value returned by a function based on the types of its tuple parameters. This allows the compiler to deduce the functionâs output type without explicit annotation, enhancing type safety and readability.
These are the following approaches:
Table of Content
- Using Conditional Type
- Using ReturnType with Function Type
- Using Inference with Tuple Parameter
Contact Us