Completed JavaScript Functional Library Project

index.js

@@ -0,0 +1,92 @@
+const myEach = function(collection, callback) {
+    for(const item of Object.values(collection)) {
+      callback(item)
+    }
+    return collection
+}
+
+const myMap = function (collection, callback) {
+  let newCollection = []
+  for(const item of Object.values(collection)) {
+    newCollection.push(callback(item))
+  }
+  return newCollection
+}
+
+const myReduce = function(collection, callback, acc) {
+  let singleValue
+  let startIndex
+
+  if (acc === undefined) {
+    const values = Object.values(collection)
+    singleValue = values[0]
+    startIndex = 1
+  } else {
+    singleValue = acc
+    startIndex = 0
+  }
+
+  const values = Object.values(collection)
+  for (let i = startIndex; i < values.length; i++) {
+    singleValue = callback(singleValue, values[i], collection)
+  }
+
+  return singleValue
+}
+
+const myFind = function(collection, predicate) {
+  for( const item of Object.values(collection)) {
+    if (predicate(item)) {
+      return item
+    }
+  }
+}
+
+const myFilter = function(collection, predicate) {
+  let newCollection = []
+  for( const item of Object.values(collection)) {
+    if (predicate(item)) {
+       newCollection.push(item)
+    }
+  }  return newCollection
+}
+
+const mySize = function(collection) {
+  let numOfItems = 0
+  for(let i = 0; i < Object.values(collection).length; i++){
+    numOfItems += 1
+  }
+  return numOfItems
+}
+
+const myFirst = function(array, n) {
+  if (n === undefined) {
+      return array[0]
+  } else {
+      return array.slice(0, n)
+  }
+}
+
+const myLast = function(array, n) {
+  if (n === undefined) {
+      return  array[array.length - 1]
+  } else {
+      return array.slice(-n)
+  }
+}
+
+const myKeys = function(object) {
+  let keys = []
+  for(const item in object) {
+    keys.push(item)
+  }
+  return keys
+}
+
+const myValues = function(object) {
+  let values = []
+  for(const item in object) {
+    values.push(object[item])
+  }
+  return values
+}