ANGULAR in less than 128 words – TypeScript – Part 4

This article follows on from the first three on the subject ANGULAR and deals with the TypeScript language:

• http://128mots.com/index.php/2020/02/29/angular-en-moins-de-128-mots-typescript-partie-3/
• http://128mots.com/index.php/2020/02/28/angular-en-moins-de-128-mots-partie-2/
• http://128mots.com/index.php/2020/02/27/angular-en-plus-de-128-mots-partie-1/

Concept of "assertion type"

Type assertion is a way to tell the TypeScript compiler what type of variable is. Type assertion is similar to type conversion in other languages, but in TypeScript, it's just a compilation function.

let testComplete: any - "Test Assertion type";
let test -<string>(complete test). substring (0.4);</string>
console.log(s);

Other ratings:

and full test: any - "Test Assertion type";
let test - (testComplete as string).substring (0.4);
console.log(s);

Arrow Function:

The use of function arrow removes the need to use the keyword "function." The settings are switched between brackets <> and the function expression is placed in brackets.

let addition - (a: number, b: number): number
            return a b;
}
addition (1, 2);

In line annotation:

In TypeScript, online type annotations allow you to declare an object for each of the object's properties.

Other use:

let addition - (pairDeNombre - numberA: number,numberB: number' number: number
            return a b;
}

Interface:

Interfaces allow you to name these types and are a powerful way to define contracts in your code as well as contracts with code outside of your project.

Point interface
  x: number,
  y: number
}

Link to TypeScript documentation: https://www.typescriptlang.org/docs/home.html