How to useConditional Types in Typescript
In this approach, we utilize conditional types to define the NestedObject<T> type. It checks if the input type T extends object. If so, it iterates over each property K of T and applies the NestedObject type recursively. Otherwise, it assigns the original type. This approach provides another way to achieve strong typing for nested object keys, offering flexibility in type definitions.
Example: This example shows the use of the above-explained approach.
Javascript
// Define a generic type for nested // objects using conditional typestype NestedObject<T> = T extends object ? { [K in keyof T]: NestedObject<T[K]> } : T;// Define a nested object typetype Product = { id: number; name: string; details: { price: number; description: string; };};// Utilize NestedObject type to // create a strongly typed nested objecttype TypedProduct = NestedObject<Product>;// Usageconst product: TypedProduct = { id: 1, name: "Laptop", details: { price: 99999, description: "High-performance laptop with SSD storage", },};console.log(product.details.price); |
Output:
99999
How to Define Strongly Type Nested Object Keys with Generics in TypeScript ?
We will look into the effective use of generics in TypeScript to ensure type safety when working with nested objects. By employing generics, developers can establish strongly typed keys for nested objects, significantly reducing the likelihood of runtime errors and enhancing code maintainability.
Table of Content
- Using Recursive Generics
- Using Conditional Types
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