Write your pollyfill of Map, Call , Apply, Bind without help of es6

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Map Function:-

Array.prototype.myMap = function (callback) {
 const newArray = [];
 for(const item of this) {
 newArray.push(callback(item));
 }
 return newArray;
};

Call Function:-

Function.prototype.myCall = function(obj) {
   obj = obj || global;
   var id = "00" + Math.random();
  while (obj.hasOwnProperty(id)) {
    id = "00" + Math.random();
  }
  obj[id] = this;
  let arg=[];
  for(let i=1;i<arguments.length;i++){
       arg.push("arguments[" + i + "]");
  }
 result= eval("obj[id]("+arg+")");
  delete obj[id];
  return result;
}

Apply function:-

Function.prototype.myApply = function(obj, argArr) {
 obj = obj || global;
 var id = "00" + Math.random();
 while (obj.hasOwnProperty(id)) {
  id = "00" + Math.random();
 }
 obj[id] = this;
 let arg=[];
 let result
 if(!argArr){
  result= obj[id].fn();
 }
 else{
  for(let i=0;i<argArr.length;i++){
      arg.push("argArr[" + i + "]");
     }
  result= eval("obj[id]("+arg+")");
  delete obj[id];
}
return result;

}

Bind function:-

Function.prototype.myBind2= function(){
  let obj1= this;
  const obj= Array.prototype.slice.call(arguments,0,1);
   const arg= Array.prototype.slice.call(arguments,1);
  return function(){
    const arg2= Array.prototype.slice.call(arguments);
   obj1.apply(obj[0],Array.prototype.concat(arg, arg2));
}

Another solution: we can pass object as argument of function

Function.prototype.myBind2 = function(obj) {
  let fn = this;
  const arg = Array.prototype.slice.call(arguments, 1);
  return function() {
    const arg2 = Array.prototype.slice.call(arguments);
    fn.apply(obj, Array.prototype.concat(arg, arg2));
  }

Another solution using es6 (spread operator):-

Function.prototype.myBind= function(obj,...arg){
let obj1= this;
return function(...arg2){
  obj1.apply(obj, [...arg, ...arg2]);
  }
}