JSFiddle - React, Tailwind, and code Playground

JavaScript

function calculator(firstNumber){
	this.firstNumber = firstNumber
  	this.result = firstNumber;
	
}

calculator.prototype.sum = function(){

for(var i = 0; i < arguments.length; i++){
			this.result = this.result+arguments[i]
		}
		return this.result
}


let c = new calculator(100)
console.log(c.sum(1,2))
console.log(c.sum(1,2))
console.log(c.sum(1,2))