Is TypeScript the ultimate solution for function typing?

Question

Is TypeScript the ultimate solution for function typing?

Currently delving into TypeScript, and I've got a query regarding annotating function types.

Taking a look at this basic example:

export const add = (num1: number, num2: number):number => {
  return num1 + num2;
};

This seems well-typed to me. Types are defined for the arguments and the return type of the function as well.

Now let's consider another valid syntax:

export const add2:(num1: number, num2: number) => number = (num1, num2) => {
  return num1 + num2;
};

In this case, we're typing the variable add2 itself. It appears that my linter is satisfied with no missing return types in either case.

I could even combine both approaches:

export const add3:(num1: number, num2: number) => number = (num1: number, num2: number):number => {
  return num1 + num2;
};

My question remains - what are the advantages or disadvantages of using approaches 1, 2, or 3 here? Is there a more commonly used style among them?

typescript

Answer 1

Answer №1

When creating a new variable and assigning it within the same statement, there is no need to explicitly define the type as it will be inferred automatically. In the scenarios presented in your query, the first option would be the most efficient choice.

If you find yourself needing to declare a variable first and assign a value or function to it later on, a cleaner approach would be to utilize Interfaces. Here's an example:

interface AddFunction {
  (number1: number, number2: number): number;
}

let addFunc: AddFunction;
addFunc = (x: number, y: number): number => x + y;
addFunc(3, 4);

Answer 2

When creating a new variable and assigning it within the same statement, there is no need to explicitly define the type as it will be inferred automatically. In the scenarios presented in your query, the first option would be the most efficient choice.

If you find yourself needing to declare a variable first and assign a value or function to it later on, a cleaner approach would be to utilize Interfaces. Here's an example:

interface AddFunction {
  (number1: number, number2: number): number;
}

let addFunc: AddFunction;
addFunc = (x: number, y: number): number => x + y;
addFunc(3, 4);

Is TypeScript the ultimate solution for function typing?

Answer №1

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