fun-fun-function-reduce-3

reduce1.js

//  mission: summarize the amount
// reduce is multi tool on list transformation

var orders = [
  {amount: 250},
  {amount: 400},
  {amount: 100},
  {amount: 325}
]

// similar to erlang tail recursion
// if we do a console.log inside the function it becomes more clear
var totalAmt = orders.reduce(function(sum, order) {
  console.log("hello", sum, order)
  return sum + order.amount
}, 0)

// using arrow functions
var totalAmt2 = orders.reduce((sum, order) => sum + order.amount, 0)


console.log(totalAmt)
console.log(totalAmt2)

/* solving the problem using for loop
var totalAmt = 0
for (var i = 0; i < order.length; i++) {
  totaltAmt += orders[i].amount
}
*/