Generic Functions in Practice
When you need to create utility functions that work with different data types while maintaining type safety, generic functions in TypeScript are the answer. A generic function lets you define a placeholder type variable, often called T, which stands for "type." You can use this type variable within the function's parameters and return type. This way, the function adapts to the type of data it receives, ensuring that the TypeScript compiler checks types correctly.
12345678// Generic function to return the first element of an array function firstElement<T>(arr: T[]): T | undefined { return arr[0]; } // Usage examples: const num = firstElement([10, 20, 30]); // num: number | undefined const str = firstElement(["a", "b", "c"]); // str: string | undefined
Generic functions make your utility code more flexible and reusable. By writing functions that can operate on any type, you avoid duplicating logic for each specific type you might encounter. This approach leads to code that is both safer and easier to maintain, since TypeScript enforces type correctness no matter what types you use with your generic function.
12345678// Generic function to merge two objects of the same type function mergeObjects<T>(obj1: T, obj2: T): T { return { ...obj1, ...obj2 }; } // Usage example: const merged = mergeObjects({ name: "Alice" }, { age: 30 }); // merged: { name: string; age: number }
TypeScript is often able to infer the type parameter for your generic function based on the arguments you provide. This means you rarely need to specify the type explicitly when calling a generic function. Instead, TypeScript analyzes the types of the arguments and fills in the generic parameter for you, keeping your code concise and easy to read.
Thanks for your feedback!
Ask AI
Ask AI
Ask anything or try one of the suggested questions to begin our chat
Can you explain how generic functions improve type safety in TypeScript?
What are some common use cases for generic functions?
How does TypeScript infer the type parameter in these examples?
Awesome!
Completion rate improved to 9.09Generic Functions in Practice
Swipe to show menu
When you need to create utility functions that work with different data types while maintaining type safety, generic functions in TypeScript are the answer. A generic function lets you define a placeholder type variable, often called T, which stands for "type." You can use this type variable within the function's parameters and return type. This way, the function adapts to the type of data it receives, ensuring that the TypeScript compiler checks types correctly.
12345678// Generic function to return the first element of an array function firstElement<T>(arr: T[]): T | undefined { return arr[0]; } // Usage examples: const num = firstElement([10, 20, 30]); // num: number | undefined const str = firstElement(["a", "b", "c"]); // str: string | undefined
Generic functions make your utility code more flexible and reusable. By writing functions that can operate on any type, you avoid duplicating logic for each specific type you might encounter. This approach leads to code that is both safer and easier to maintain, since TypeScript enforces type correctness no matter what types you use with your generic function.
12345678// Generic function to merge two objects of the same type function mergeObjects<T>(obj1: T, obj2: T): T { return { ...obj1, ...obj2 }; } // Usage example: const merged = mergeObjects({ name: "Alice" }, { age: 30 }); // merged: { name: string; age: number }
TypeScript is often able to infer the type parameter for your generic function based on the arguments you provide. This means you rarely need to specify the type explicitly when calling a generic function. Instead, TypeScript analyzes the types of the arguments and fills in the generic parameter for you, keeping your code concise and easy to read.
Thanks for your feedback!
