Mastering TypeScript 3 - Third Edition

Class constructors

Classes can accept parameters during their initial construction. This allows us to combine the creation of a class and the setting of its parameters into a single line of code. Consider the following class definition:

class ClassWithConstructor { 
    id: number; 
    name: string; 
    constructor(_id: number, _name: string) { 
        this.id = _id; 
        this.name = _name; 
    } 
}

Here, we have defined a class named ClassWithConstructor that has two properties, an id property of type number, and a name property of type string. It also has a constructor function that accepts two parameters. The constructor function is assigning the value of the _id argument to the class property of id, and the value of the _name argument to the class property, name. Note ...