Functions are like Objects

##A function is similar to objects##

• A function is an instance of the Object type
• A function can be stored in a variable
• A function can be passed as an argument to another function

First class function?

##Passing a function as an argument##

var numbers = [1,4,6,1,9]

function arrayCalc(arr,fn){
  var arrRes = [];
  for (var i = 0; i < arr.length; i++){
  arrRes.push(fn(arr[i]));
  }
  return arrRes;
} 

function calculatePower(num){
  return num**2;
}

//Calculate power without brackets since it is a call back function
arrayCalc(years,calculatePower);