function composition (function programming) over inheritance javascript with example

working link

https://stackblitz.com/edit/js-d57tvk


more about

https://www.youtube.com/results?search_query=functional+programming+vs+object+oriented+javascript


a better link

https://www.youtube.com/watch?v=7HolHe7Gqbw&t=263s


example :-

//function composition (function programming) over inheritance

//create some global function every thing except number and string are object in javascript

//@function showName----------------------------

const showName=(state)=>({

getfullName()

{

return state.name+" "+state.last;

}

});

//@function showSalary----------------------------

const showSalary=(state)=>(

{

bonus:800,

getSal()

{

return state.sal*12+this.bonus;

}

}

)

//@function what emp do

const WhatHeDo=(state)=>(

{

getType()

{

switch(state.type) {

case "it":

this.type="you are a it emp";

break;

case "game":

this.type="you are a game developer"

break;

default:

// code block

}

return this.type;

}

}

)

//emp class which is function as we know every function is a constructor in javascript

function emp(_name,_last)

{

let objRef={

name:_name,

last:_last

}

return Object.assign(objRef,showName(objRef));

}

//create a new class itEmp which hold some properties

function itEmp(_sal,_type)

{

let objRef={

sal:_sal,

type:_type

}

return Object.assign(objRef,showSalary(objRef),WhatHeDo(objRef));

}

//copy or you can say copy properties from source to destination

//where source is emp calss and destination is itEmp class

//first object

let itemp=Object.assign(itEmp(2000,"it"),emp("manish","chauhan"))

console.log(itemp.getfullName())

console.log(itemp.getSal())

console.log(itemp.getType());

//second object

let gameemp=Object.assign(itEmp(2100,"game"),emp("sachin","chauhan"))

console.log(gameemp.getfullName())

console.log(gameemp.getSal());

console.log(gameemp.getType());