TypeScript 2.x By Example

Functions

Generic functions are very similar to normal functions, except for how we specify the types used in a function. Let's take a standard function, and see how it can be converted to a generic function.

The following function takes a number as the input parameter and pushes that number into an array:

 data = []; pushNumberToArray(item: number){ this.data.push(item); }

Now, let's say that we get another requirement in the future of pushing a string into the same array. To handle this requirement, we will write another function, which takes a string as the input, as follows:

 pushStringToArray(item: string){ this.data.push(item); }

As you can see, this is not the best practice to manage the array. Every time we have a new requirement, ...