// Array :- It is collection more the single value inside an variable // forEach() : This method invoke the function for each element of array // Array.forEach(callback(value,index,arr),thisArg) const arr1=[1,2,3,4,5]; const arr2=arr1.forEach(function (value){// foreach does not return a new array return value*2; }) console.log(arr1); console.log(arr2);//this is will give the undefined output