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// currying example
var add = function(vala){
  return function(valb){
    return vala + valb;
  }
}

console.log(add(2)(2)); // outputs 4

// or more currying just not chained which is the same thing

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function allStorage() {

    var archive = [],
        keys = Object.keys(localStorage),
        i = 0, key;

    for (; key = keys[i]; i++) {
        archive.push( key + '=' + localStorage.getItem(key));
    }

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var cars = [ {make: "Nissan",
              model: "Maxima"},
             {make: "Infinity",
              model: "G60RS"}
           ];
function pluck(array, property) {
  var results = [];
  array.map(function(item){
    results.push(item[property]);
  });

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var cars = [{make: "Honda", type: "truck"},{make: "Cadillac", type: "sedan"}, {make: "McLaren", type: "coup"}, {make: "Infinity", type: "coup"}];
function reject(array, iteratorFunction) {
   return array.filter(iteratorFunction);  
}
var noCoups = reject(cars, function(car) {
    return car.type !== "coup";
});

// or numbers reusing 'filter' to reverse the effect of filter (only push items that return false)
var numbers = [10,20,30];

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var ladders= [{height: '20 feet'}, {height: '10 feet'},{height: '100 feet'}];
function findWhere(array, criteria) {
  return array.find(function(item){
      return item.height === criteria.height;
  });
}
var twentyFootLadder = findWhere(ladders, {height: '20 feet'});

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var miles = [{ distance: 34 }, { distance: 12 } , { distance: 1 }];
var totalDistance = miles.reduce(function(prev, item){return prev + item.distance;}, 0);

//return the total of sitting and standing chairs
var desks = [
  { type: 'sitting' },
  { type: 'standing' },
  { type: 'sitting' },
  { type: 'sitting' },
  { type: 'standing' }

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function makeUnique(array) {
  return array.reduce(function(prev, num) {
    if (!prev.find(function(item) { return item == num; })) { 
      prev.push(num);
    }
    return prev;
  }, []);
}
var uniqueNumbers = makeUnique([1, 6 ,5, 6, 4, 3, 3, 3, 2, 1, 1]);

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const points = [
		[1, 2],
		[50, -10],
		[110, 405]
];
points.map(([x, y]) => {
	return { x, y };	
});

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function double([number, ...rest]) {
return !number ? [] : [number * 2, ...double(rest)];
}

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function compareTriplets(a, b) {
  	let score1, score2, iter;
  	score1 = score2 = iter = 0;
    a.map(item => {
      if (item > b[iter]) {
        score1++;
      }
      if ( item < b[iter]) {
        score2++;
      }