typescript override method code example

Example 1: ts override method

class Person{
    name:string
 
    eat():void{
        console.log(this.name+" eats when hungry.")
    }
}
 
class Student extends Person{
    // variables
    rollnumber:number;
 
    // constructors
    constructor(rollnumber:number, name1:string){
        super(); // calling Parent's constructor
        this.rollnumber = rollnumber
        this.name = name1
    }
 
    // functions
    displayInformation():void{
        console.log("Name : "+this.name+", Roll Number : "+this.rollnumber)
    }
 
    // overriding super class method
    eat():void{
        console.log(this.name+" eats during break.")
    }
}
 
var student1 = new Student(2, "Rohit")
 
student1.displayInformation()
student1.eat()

Example 2: typescript override type of property

interface A {
    x: string
}

export type B = Omit<A, 'x'> & { x: number };

Example 3: typescript extension getter

interface A {
    testGet: SomeType|null;
}

Object.defineProperty(A.prototype, "testGet", {
    get (this: A) {
        if(this.something) { 
          return this.something;
        }
        return null;
    },
    enumerable: false,
    configurable: true
});