how to write functions in a class in js code example
Example 1: javascript new function as class
// Javascript Function that behaves as class, with private variables
function Person(name){
const birth = new Date();
this.greet = () => `Hello my name is ${name}. I was born at ${birth.toISOString()}`;
}
const joe = new Person("Joe");
joe.greet(); // Hello my name is Joe. I was born at 2021-04-09T21:12:33.098Z
// The birth variable is "inaccessible" from outside so "private"
Example 2: javascript class example
// to create a class named 'LoremIpsum':
class LoremIpsum {
// a function that will be called on each instance of the class
// the parameters are the ones passed in the instantiation
constructor(a, b, c) {
this.propertyA = a;
// you can define default values that way
this.propertyB = b || "a default value";
this.propertyC = c || "another default value";
}
// a function that can influence the object properties
someMethod (d) {
this.propertyA = this.propertyB;
this.propertyB = d;
}
}
// you can then call it
var loremIpsum = new LoremIpsum ("dolor", null, "sed");
// at this point:
// loremIpsum = { propertyA: 'dolor',
// propertyB: 'a default value',
// propertyC: 'sed' }
loremIpsum.someMethod("amit");
// at this point:
// loremIpsum = { propertyA: 'a default value',
// propertyB: 'amit',
// propertyC: 'sed' }
.