array reduce examples

reduce.js

basic example
var data = [30, 5],
    initialValue = 0;
    reducer = function(accumulator, initialValue){
      return accumulator + initialValue;
    }

var newData = data.reduce(reducer, initialValue);
console.log('new data is', newData);

var votes = [
  'react',
  'angular',
  'angular',
  'react',
  'react',
  'ember',
  'vanilla'
],

initialValue = {},
reducer = function(tally, vote){
  if(!tally[vote]) {
    tally[vote] = 1;
  } else {
    tally[vote] = tally[vote] + 1;
  }
  return tally;
}

  result = votes.reduce(reducer, initialValue);

  console.log('finally totals are', result);



var data = [1, 2, 3, 4, 5];
var double = data.reduce(function(acc, value){
  acc.push(value * 2);
  return acc;
}, []);
console.log(double);