ARRAYS+CALLBACKS+CLOSURE+FUNC-CONVERSATION

Witanday · Witanday · commit 219c3f5a73ff · 2018-08-19T20:27:09.000-04:00
diff --git a/assignments/array-methods.js b/assignments/array-methods.js
@@ -55,6 +55,7 @@ const runners = [{"id":1,"first_name":"Charmain","last_name":"Seiler","email":"c
 
 // ==== Challenge 1: Use .forEach() ====
 // The event director needs both the first and last names of each runner for their running bibs.  Combine both the first and last names into a new array called fullName. 
+
 let fullName = [];
 runners.forEach( (val) =>{
   fullName.push(`${val.first_name} ${val.last_name} `)
@@ -65,33 +66,22 @@ console.log(fullName);
 // ==== Challenge 2: Use .map() ====
 // The event director needs to have all the runner's first names converted to uppercase because the director BECAME DRUNK WITH POWER. Convert each first name into all caps and log the result
 let allCaps = [];
-runners.map( (val) =>{
-  allCaps.push(`${(val.first_name).toUpperCase()} ${val.last_name} `)
-}
-)
+runners.map( (val) =>{ allCaps.push(`${(val.first_name).toUpperCase()} ${val.last_name} `)})
 console.log(allCaps); 
 
 // ==== Challenge 3: Use .filter() ====
 // The large shirts won't be available for the event due to an ordering issue.  Get a list of runners with large sized shirts so they can choose a different size. Return an array named largeShirts that contains information about the runners that have a shirt size of L and log the result
 let largeShirts = [];
-runners.filter( (val) =>{
- return (val.shirt_size === 'L' ? largeShirts.push(val) :false)})
+largeShirts = runners.filter( (val) =>{
+ return val.shirt_size === 'L' })
 
 console.log(largeShirts);
 
 // ==== Challenge 4: Use .reduce() ====
 // The donations need to be tallied up and reported for tax purposes. Add up all the donations into a ticketPriceTotal array and log the result
 let ticketPriceTotal = [];
-let price = [];
-runners.map( (val) =>{
-  price.push(val.donation)
-});
-
-const x = price.reduce( (accumulator, nextvalue) =>{ 
-
-  return accumulator + nextvalue;
-  });
-  ticketPriceTotal.push(x)
+ticketPriceTotal   = runners.reduce( (accumulator, nextvalue) =>{ return accumulator + nextvalue.donation; }, 0);
+  
 console.log( ticketPriceTotal);
 
 // ==== Challenge 5: Be Creative ====
diff --git a/assignments/callbacks.js b/assignments/callbacks.js
@@ -2,33 +2,91 @@ const items = ['Pencil', 'Notebook', 'yo-yo', 'Gum'];
 
 function firstItem(arr, cb) {
   // firstItem passes the first item of the given array to the callback function.
+ return cb(arr) ;
 }
+function getFirstItem (arr) {
+   return arr[0];
+}
+console.log(firstItem(items, getFirstItem)) 
+
+///////////////////////////////////////////////////////
+
 
 function getLength(arr, cb) {
   // getLength passes the length of the array into the callback.
+  return cb(arr) ;
 }
+function lengthArr (arr) {
+  return arr.length;
+}
+console.log(firstItem(items, lengthArr)) 
+
+/////////////////////////////////
 
 function last(arr, cb) {
   // last passes the last item of the array into the callback.
+
+return cb(arr) ;
+}
+function getLastItem (arr) {
+   return arr[arr.length - 1];
 }
+console.log(firstItem(items,  getLastItem )) 
+
+///////////////////////////////////////
 
 function sumNums(x, y, cb) {
   // sumNums adds two numbers (x, y) and passes the result to the callback.
+  return cb(x, y);
+}
+function getSum (a, b) {
+  return a + b ;
 }
+console.log(sumNums(150, 200, getSum)) 
+
+///////////////////////////////////////////////
 
 function multiplyNums(x, y, cb) {
   // multiplyNums multiplies two numbers and passes the result to the callback.
+  return cb(x, y);
+}
+function getMultiply (a, b) {
+  return a * b ;
 }
+console.log(multiplyNums(150, 200, getMultiply)) 
+
+//////////////////////////////////////////////
 
 function contains(item, list, cb) {
   // contains checks if an item is present inside of the given array/list.
   // Pass true to the callback if it is, otherwise pass false.
+  return cb(item,list);
 }
+function getItemfromList(item, arr) {
+  return arr.indexOf(item) !== -1 ? true : false ;
+}
+console.log(contains( 'hello', [1, 45, 5, 10, 'hello'], getItemfromList));
+
 
 /* STRETCH PROBLEM */
 
 function removeDuplicates(array, cb) {
   // removeDuplicates removes all duplicate values from the given array.
   // Pass the duplicate free array to the callback function.
   // Do not mutate the original array.
+
+  return cb(array) ;
+
+}
+
+function noDuplicate (arr){
+  let newArr = [];
+  arr.forEach(function(item) {
+       if(newArr.indexOf(item) < 0) {
+            newArr.push(item) 
+       }
+       
+  });
+  return newArr;
 }
+console.log(removeDuplicates(  [1, 45, 5, 10, 'hello', 14, 5, 1, 5, 10 ], noDuplicate))
diff --git a/assignments/closure.js b/assignments/closure.js
@@ -1,15 +1,40 @@
+
 // ==== Challenge 1: Write your own closure ====
 // Write a simple closure of your own creation.  Keep it simple!
+function cspt2 (){
+  let instructors = [ 'Dan', 'Moses', 'Raymond'];
+  return {
+    getInstructors :  () => {
+      return instructors;
+    },
+    addInstructor : (instructor) => {
+      instructors.push(instructor);
+      return instructors;
+    }
+  }
+}
+console.log(cspt2 ().getInstructors());
+console.log(cspt2 ().addInstructor ('NewInstructor'));
+
 
 
 // ==== Challenge 2: Create a counter function ====
 const counter = () => {
   // Return a function that when invoked increments and returns a counter variable.
+  let count = 0;
+  return () => {
+    count ++
+    return count;
+  }
+
 };
+
+console.log(counter ()());
+
+
 // Example usage: const newCounter = counter();
 // newCounter(); // 1
 // newCounter(); // 2
-
 /* STRETCH PROBLEM, Do not attempt until you have completed all previous tasks for today's project files */
 
 // ==== Challenge 3: Create a counter function with an object that can increment and decrement ====
diff --git a/assignments/function-conversion.js b/assignments/function-conversion.js
@@ -1,23 +1,38 @@
 // Take the commented ES5 syntax and convert it to ES6 arrow Syntax
 
 // let myFunction = function () {};
+let myFunction =  () => {};
+
 
 // let anotherFunction = function (param) {
 //   return param;
 // };
 
+let anotherFunction =  (param) =>  param;
+ 
+
 // let add = function (param1, param2) {
 //   return param1 + param2;
 // };
 // add(1,2);
 
+let add =  (param1, param2) => param1 + param2;
+ add(1,2);
+
 // let subtract = function (param1, param2) {
 //   return param1 - param2;
 // };
 // subtract(1,2);
 
+let subtract =  (param1, param2) => param1 - param2;
+subtract(1,2);
+
 // exampleArray = [1,2,3,4];
 // const triple = exampleArray.map(function (num) {
 //   return num * 3;
 // });
-// console.log(triple);
+// console.log(triple);
+
+const exampleArray = [1,2,3,4];
+ const triple = exampleArray.map( (num) => num * 3);
+ console.log(triple);
