Completed High Order Functions Practice

.js

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+// This repo is optional extra practice to use the underscore functions.
+// Here we'll be writing new functions, but these functions will use
+// the underscore functions within them.
+
+// If you would like to take a look at the inputs that are passed into these functions, please
+// feel free to check out the data.js file.
+
+/*
+ *
+ *  _.each
+ *
+ */
+
+// use _.each to create a copy of the given array.
+var moreFruits = function (fruits) {
+  var results = [];
+
+  _.each(fruits, function(fruit, index, collection) {
+    results.push(fruit);
+  });
+
+  return results;
+};
+
+// use _.each to traverse the number array and determine
+// which are multiples of five.
+//i- array of numbers
+//o- count of multiple of 5
+//c
+//e
+var multiplesOfFive = function (numbers) {
+  var count5 = 0;
+  _.each(numbers, function(n, index, numbers) {
+    if (n % 5 === 0) {
+      count5++;
+    }
+  });
+  return count5;
+};
+
+// use _.each to build an array containing only tweets belonging to a specified user.
+//i- array of tweet objects, user value
+//o - array of tweets by user
+//c -
+//e -
+
+var getUserTweets = function(tweets, user) {
+  //iterate through _.each tweets to find which one has matching user object value
+  var newArr = [];
+  _.each(tweets, function(tweet, index, tweets) {
+    if (tweet.user === user) {
+      newArr.push(tweet);
+    }
+  });
+  return newArr;
+};
+
+/*
+ *
+ *  _.filter
+ *
+ */
+
+// use _.filter to return the fruits array with only the desired fruit.
+var onlyOneFruit = function (fruits, targetFruit) {
+  //filter fruits to find targetFruit
+  return _.filter(fruits, function (fruit, index, fruits) {
+    return fruit === targetFruit;
+  });
+};
+
+// use _.filter to return the fruits array with only fruits
+// starting with the letter 'P'.
+var startsWith = function (fruits, letter) {
+  //filter fruits to see if str starts with letter
+  return _.filter(fruits, function(fruit) {
+    return fruit[0] === letter;
+  });
+};
+
+// return a filtered array containing only cookie-type desserts.
+var cookiesOnly = function (desserts) {
+  //filter desserts array of objects, return item.type if it is cookie
+  return _.filter(desserts, function(item) {
+    return item.type === 'cookie';
+  });
+
+};
+
+//i - an array of tweet objects
+//o - array of users tweets
+//c
+//e
+// rebuild the getUserTweets function from above with _.filter instead
+var filterUserTweets = function(tweets, user) {
+  //filter tweets to find tweet by user
+  return _.filter(tweets, function (tweet) {
+    return tweet.user === user;
+  });
+};
+
+/*
+ *
+ *  _.map
+ *
+ */
+
+// given an array of strings, use _.map to return a new array containing all
+// strings converted to uppercase letters
+//i - array of fruits
+//o- newArr with strings to upper case
+var upperCaseFruits = function (fruits) {
+  var result = _.map(fruits, function(fruit) {
+    return fruit.toUpperCase();
+  });
+  console.log(result);
+  return result;
+};
+
+// given an array of dessert objects, return a new array of objects
+// that have a new "glutenFree" property, with a boolean value.
+// TIP: Items that contain flour are not gluten-free.
+//i- array of dessert objects
+//o- new array of objects that glutenFree is true
+var glutenFree = function (desserts) {
+  //if dessert ingredients doesn't include gluten, map
+  var result =  _.map(desserts, function(dessert) {
+    if (!dessert.ingredients.includes('flour')) {
+      return dessert['glutenFree'] = true;
+    }
+  });
+
+  return result;
+};
+
+// given an array of tweet objects, return a new array of strings
+// containing only the message properties.
+var allUserMessages = function(tweets) {
+
+};
+
+// use _.map to return an array of items with their sale prices, with a new property
+// containing the sale price. round any decimals to 2 places.
+//
+// having trouble with decimals? check out this article:
+// http://adripofjavascript.com/blog/drips/avoiding-problems-with-decimal-math-in-javascript.html
+//
+/*
+
+ example output:
+  var salePrices = applyCoupon(groceries, 0.20);
+  [
+    {
+      id: 1,
+      product: 'Olive Oil',
+      price: '$12.1',
+      salePrice: '$9.68'
+    }
+  ];
+
+*/
+var applyCoupon = function (groceries, coupon) {
+
+};
+
+/*
+ *
+ *  _.reduce
+ *
+ */
+
+// return the total price of all products.
+var sumTotal = function (products) {
+
+};
+
+// return an object consisting of dessert types and how many of each.
+// exampleOutput: { dessertType: 3, dessertType2: 1 }
+var dessertCategories = function (desserts) {
+
+};
+
+// return an object with the proper count of all user messages
+/*
+ example output:
+  var tweetCountPerUser = countMessagesPerUser(tweets);
+  {
+    "douglascalhoun": 5,
+    "mracus": 6,
+    "shawndrost": 5,
+    "sharksforcheap": 3
+  }
+*/
+var countMessagesPerUser = function(tweets) {
+
+};
+
+// given an array of movie data objects,return an array containing
+// movies that came out between 1990 and 2000.
+// TIP: use an array as your accumulator - don't push to an external array!
+var ninetiesKid = function (movies) {
+
+};
+
+// return an boolean stating if there exists a movie with a shorter
+// runtime than your time limit.
+// timeLimit is an integer representing a number of minutes.
+var movieNight = function (movies, timeLimit) {
+
+};