How to use Type constraints In Typescript

You can specify constraints on the type parameter to ensure that only certain types are accepted.

Syntax:

function functionName<T>(parameter1: T, parameter2: T, ...): ReturnType {
    // Function body
}

Example: The type constraint { length: number } ensures that only objects with a length property of type number can be passed to the printLength function. This prevents runtime errors by catching invalid types at compile time.

Javascript

function printLength<T extends { length: number }>
    (obj: T): void {
    console.log("Length:", obj.length);
}

printLength("hello");
printLength([1, 2, 3]);
printLength({ length: 5, width: 3 });
printLength(123);

Output:

Length: 5
Length: 3
Length: 5
 Error: Type 'number' does not have a property 'length'

How to Create TypeScript Generic Function with Safe Type Matching ?

In TypeScript, generic functions offer a powerful tool for creating flexible and reusable code that can work with various data types. However, ensuring type safety is crucial to prevent runtime errors and maintain code reliability.