finished arrays

Ryan Hamblin · Ryan Hamblin · commit 9b45d28e65c5 · 2017-07-28T13:16:26.000-06:00
diff --git a/src/arrays.js b/src/arrays.js
@@ -8,33 +8,67 @@ const each = (elements, cb) => {
   // Iterates over a list of elements, yielding each in turn to the `cb` function.
   // This only needs to work with arrays.
   // based off http://underscorejs.org/#each
+  for (let i = 0; i < elements.length; i++) {
+    cb(elements[i], i);
+  }
 };
 
 const map = (elements, cb) => {
+  const myArr = [];
+  each(elements, (el, i) => {
+    myArr.push(cb(el, i));
+  });
+  return myArr;
   // 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, memo) => {
+const reduce = (elements, cb, memo = elements.shift()) => {
   // Combine all elements into a single value going from left to right.
   // Elements will be passed one by one into `cb`.
   // `memo` is the starting value.  If `memo` is undefined then make `elements[0]` the initial value.
+  each(elements, (item) => {
+    memo = cb(memo, item);
+  });
+  return memo;
 };
 
 const find = (elements, cb) => {
   // 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.
+  let flag;
+  elements.forEach((element) => {
+    if (cb(element)) flag = element;
+  });
+  return flag;
 };
 
 const filter = (elements, cb) => {
   // 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
+  const returnArr = [];
+  elements.forEach((element) => {
+    if (cb(element)) returnArr.push(element);
+  });
+  return returnArr;
 };
 
 const flatten = (elements) => {
   // Flattens a nested array (the nesting can be to any depth).
   // Example: flatten([1, [2], [3, [[4]]]]); => [1, 2, 3, 4];
+  const newArr = [];
+  elements.forEach((element) => {
+    if (Array.isArray(element)) {
+      const nest = flatten(element);
+      nest.forEach((nestedEl) => {
+        newArr.push(nestedEl);
+      });
+    } else {
+      newArr.push(element);
+    }
+  });
+  return newArr;
 };
 
 /* eslint-enable no-unused-vars, max-len */
