JP Emery: Javascript-I completed tests, Objects.js is correct

Siddartha08 · Siddartha08 · commit 10207f031966 · 2018-01-11T23:29:00.000-06:00
diff --git a/src/arrays.js b/src/arrays.js
@@ -15,20 +15,27 @@ const each = (elements, cb) => {
 };
 
 const map = (elements, cb) => {
-  function multiplyByTwo(item) {
-    return item * 2;
-  }
-  const newArr = elements.map(multiplyByTwo);
-  return cb(newArr);
+  const newArr = [];
 
+  for (let i = 0; i < elements.length; i++) {
+    newArr.push(cb(elements[i]));
+  }
+  return newArr;
   // Produces a new array of values by mapping each value in list through a transformation function (iteratee).
   // Return the new array.
 };
 
 const reduce = (elements, cb, startingValue) => {
-  for (let i = 0; i < elements.length; i++) {
-    const callbackItem = cb(startingValue, elements[i]);
+  let startingIndex = 0;
+  if (startingValue === undefined) {
+    startingValue = elements[0];
+    startingIndex = 1;
+  }
+  for (let i = startingIndex; i < elements.length; i++) {
+    startingValue = cb(startingValue, elements[i]);
   }
+
+  return startingValue;
   // Combine all elements into a single value going from left to right.
   // Elements will be passed one by one into `cb` along with the `startingValue`.
   // `startingValue` should be the first argument passed to `cb` and the array element should be the second argument.
@@ -37,23 +44,40 @@ const reduce = (elements, cb, startingValue) => {
 
 const find = (elements, cb) => {
   for (let i = 0; i < elements.length; i++) {
-    const returning = cb(elements[i]);
-    return returning;
+    if (cb(elements[i] === true)) {
+      return elements[i];
+    }
   }
+  return undefined;
   // Look through each value in `elements` and pass each element to `cb`.
   // If `cb` returns `true` then return that element.
   // Return `undefined` if no elements pass the truth test.
 };
 
 const filter = (elements, cb) => {
-
+  const newArr = [];
+  for (let i = 0; i < elements.length; i++) {
+    if (cb(elements[i])) {
+      newArr.push(elements[i]);
+    }
+  }
+  return newArr;
   // Similar to `find` but you will return an array of all elements that passed the truth test
   // Return an empty array if no elements pass the truth test
 };
 
 /* STRETCH PROBLEM */
 
 const flatten = (elements) => {
+  const newArr = [];
+  for (let i = 0; i < elements.length; i++) {
+    if (Array.isArray(elements[i])) {
+      newArr.concat(flatten(elements[i]));
+    } else {
+      newArr.concat(elements[i]);
+    }
+  }
+  return newArr;
   // Flattens a nested array (the nesting can be to any depth).
   // Example: flatten([1, [2], [3, [[4]]]]); => [1, 2, 3, 4];
 };
diff --git a/src/callbacks.js b/src/callbacks.js
@@ -59,7 +59,16 @@ const contains = (item, list, cb) => {
 /* STRETCH PROBLEM */
 
 const removeDuplicates = (array, cb) => {
-  // removeDuplicates removes all duplicate values from the given array.
+
+  let newArr = [];
+  for (let i = 0 ; i < array.length; i++) {
+let index = newArr.indexOf(array[i]);
+if(index === -1) {
+  newArr.push(array[i]);
+}
+} 
+return cb(newArr);
+ // removeDuplicates removes all duplicate values from the given array.
   // Pass the duplicate free array to the callback function.
   // Do not mutate the original array.
 };
diff --git a/src/closure.js b/src/closure.js
@@ -1,26 +1,62 @@
 // Complete the following functions.
 
 const counter = () => {
+  let count = 1;
+  function increments() {
+    return count++;
+  }
+  return increments;
   // Return a function that when invoked increments and returns a counter variable.
   // Example: const newCounter = counter();
   // newCounter(); // 1
   // newCounter(); // 2
 };
 
 const counterFactory = () => {
+  let count = 0;
+
+  return {
+    increment: () => {
+      return ++count;
+    },
+    decrement: () => {
+      return --count;
+    },
+  };
   // Return an object that has two methods called `increment` and `decrement`.
   // `increment` should increment a counter variable in closure scope and return it.
   // `decrement` should decrement the counter variable and return it.
 };
 
 const limitFunctionCallCount = (cb, n) => {
+  let count = n;
+
+  return () => {
+    if (count > 0) {
+      --count;
+      return cb();
+    }
+    return null;
+  };
   // Should return a function that invokes `cb`.
   // The returned function should only allow `cb` to be invoked `n` times.
 };
 
 /* STRETCH PROBLEM */
 
 const cacheFunction = (cb) => {
+  const cache = {};
+  return (...args) => {
+    const keys = Object.keys(cache);
+    const argsString = args.toString();
+    if (keys.indexOf(argsString) !== -1) {
+      return cache[argsString];
+    }
+    const result = cb(...args);
+    cache[argsString] = result;
+    return result;
+  };
+
   // Should return a funciton that invokes `cb`.
   // A cache (object) should be kept in closure scope.
   // The cache should keep track of all arguments have been used to invoke this function.
diff --git a/src/objects.js b/src/objects.js
@@ -2,29 +2,33 @@
 // Reference http://underscorejs.org/ for examples.
 
 const keys = (obj) => {
-  for (let i = 0; i < Object.keys(obj).length; i++) {
-    const value = [];
-    value.push(Object.keys(obj[i]));
-    return value;
-  }
-  return value;
+  return Object.keys(obj);
   // Retrieve all the names of the object's properties.
   // Return the keys as strings in an array.
   // Based on http://underscorejs.org/#keys
 };
 
 const values = (obj) => {
+  return Object.values(obj);
   // Return all of the values of the object's own properties.
   // Ignore functions
   // http://underscorejs.org/#values
 };
 
 const mapObject = (obj, cb) => {
+  const newObj = {};
+  const key = Object.keys(obj);
+  for (let i = 0; i < key.length; i++) {
+    const newVal = cb(obj[key[i]]);
+    newObj[key[i]] = newVal;
+  }
+  return newObj;
   // Like map for arrays, but for objects. Transform the value of each property in turn.
   // http://underscorejs.org/#mapObject
 };
 
 const pairs = (obj) => {
+  return Object.entries(obj);
   // Convert an object into a list of [key, value] pairs.
   // http://underscorejs.org/#pairs
 };
@@ -38,6 +42,7 @@ const invert = (obj) => {
 };
 
 const defaults = (obj, defaultProps) => {
+  Object.assign(defaultProps, obj);
   // Fill in undefined properties that match properties on the `defaultProps` parameter object.
   // Return `obj`.
   // http://underscorejs.org/#defaults
