diff --git a/assignments/array-methods.js b/assignments/array-methods.js index f3862361e..396701956 100644 --- a/assignments/array-methods.js +++ b/assignments/array-methods.js @@ -1,85 +1,536 @@ -// A local community center is holding a fund raising 5k fun run and has invited 50 small businesses to make a small donation on their behalf for some much needed updates to their facilities. Each business has assigned a representative to attend the event along with a small donation. +//* A local community center is holding a fund raising 5k fun run and has invited 50 small businesses to make a small donation on their behalf for some much needed updates to their facilities. Each business has assigned a representative to attend the event along with a small donation. -// Scroll to the bottom of the list to use some advanced array methods to help the event director gather some information from the businesses. +//* Scroll to the bottom of the list to use some advanced array methods to help the event director gather some information from the businesses. const runners = [ - { id: 1, first_name: "Charmain", last_name: "Seiler", email: "cseiler0@wired.com", shirt_size: "2XL", company_name: "Divanoodle", donation: 75 }, - { id: 2, first_name: "Whitaker", last_name: "Ierland", email: "wierland1@angelfire.com", shirt_size: "2XL", company_name: "Wordtune", donation: 148 }, - { id: 3, first_name: "Julieta", last_name: "McCloid", email: "jmccloid2@yahoo.com", shirt_size: "S", company_name: "Riffpedia", donation: 171 }, - { id: 4, first_name: "Martynne", last_name: "Paye", email: "mpaye3@sciencedaily.com", shirt_size: "XL", company_name: "Wordware", donation: 288 }, - { id: 5, first_name: "Gussy", last_name: "Raraty", email: "graraty4@ucoz.ru", shirt_size: "L", company_name: "Oozz", donation: 291 }, - { id: 6, first_name: "Yule", last_name: "Tommasetti", email: "ytommasetti5@state.gov", shirt_size: "S", company_name: "Yodo", donation: 27 }, - { id: 7, first_name: "Kathie", last_name: "Majury", email: "kmajury6@guardian.co.uk", shirt_size: "3XL", company_name: "Zoomcast", donation: 261 }, - { id: 8, first_name: "Tanner", last_name: "Branton", email: "tbranton7@tmall.com", shirt_size: "2XL", company_name: "Realmix", donation: 28 }, - { id: 9, first_name: "Sarina", last_name: "Lasham", email: "slasham8@toplist.cz", shirt_size: "XL", company_name: "Gigashots", donation: 110 }, - { id: 10, first_name: "Bertie", last_name: "Lonergan", email: "blonergan9@issuu.com", shirt_size: "3XL", company_name: "Skinte", donation: 62 }, - { id: 11, first_name: "Trevor", last_name: "Studd", email: "tstudda@networkadvertising.org", shirt_size: "S", company_name: "Cogidoo", donation: 76 }, - { id: 12, first_name: "Malachi", last_name: "Okeshott", email: "mokeshottb@chron.com", shirt_size: "M", company_name: "DabZ", donation: 91 }, - { id: 13, first_name: "Berget", last_name: "Logsdail", email: "blogsdailc@wix.com", shirt_size: "M", company_name: "Mymm", donation: 9 }, - { id: 14, first_name: "Loise", last_name: "Rivlin", email: "lrivlind@behance.net", shirt_size: "2XL", company_name: "Linktype", donation: 204 }, - { id: 15, first_name: "Christan", last_name: "Kendall", email: "ckendalle@example.com", shirt_size: "XS", company_name: "Skinix", donation: 252 }, - { id: 16, first_name: "Kayla", last_name: "Whitwam", email: "kwhitwamf@deliciousdays.com", shirt_size: "2XL", company_name: "Oyope", donation: 147 }, - { id: 17, first_name: "Heddie", last_name: "Heningam", email: "hheningamg@tripadvisor.com", shirt_size: "L", company_name: "Skinix", donation: 172 }, - { id: 18, first_name: "Mace", last_name: "Ballinger", email: "mballingerh@a8.net", shirt_size: "S", company_name: "Nlounge", donation: 266 }, - { id: 19, first_name: "Nola", last_name: "Abberley", email: "nabberleyi@jalbum.net", shirt_size: "XL", company_name: "Photospace", donation: 148 }, - { id: 20, first_name: "Nadine", last_name: "Tresler", email: "ntreslerj@marketwatch.com", shirt_size: "3XL", company_name: "Wikido", donation: 292 }, - { id: 21, first_name: "Ulrikaumeko", last_name: "Vuittet", email: "uvuittetk@gov.uk", shirt_size: "S", company_name: "Skinte", donation: 102 }, - { id: 22, first_name: "Saunder", last_name: "Spennock", email: "sspennockl@icq.com", shirt_size: "3XL", company_name: "Kwimbee", donation: 213 }, - { id: 23, first_name: "Carmel", last_name: "Woffinden", email: "cwoffindenm@wikispaces.com", shirt_size: "S", company_name: "Rooxo", donation: 137 }, - { id: 24, first_name: "Marielle", last_name: "Kimmel", email: "mkimmeln@jimdo.com", shirt_size: "M", company_name: "Livetube", donation: 96 }, - { id: 25, first_name: "Brucie", last_name: "Burris", email: "bburriso@slate.com", shirt_size: "2XL", company_name: "Wordtune", donation: 128 }, - { id: 26, first_name: "Juan", last_name: "Berzon", email: "jberzonp@soup.io", shirt_size: "3XL", company_name: "Einti", donation: 234 }, - { id: 27, first_name: "Sacha", last_name: "Olsen", email: "solsenq@reverbnation.com", shirt_size: "2XL", company_name: "Viva", donation: 190 }, - { id: 28, first_name: "Jamey", last_name: "O'Nolan", email: "jonolanr@samsung.com", shirt_size: "XL", company_name: "Skinix", donation: 31 }, - { id: 29, first_name: "Morrie", last_name: "Rainard", email: "mrainards@yale.edu", shirt_size: "XS", company_name: "Podcat", donation: 52 }, - { id: 30, first_name: "Fidel", last_name: "Roskelly", email: "froskellyt@ibm.com", shirt_size: "XS", company_name: "Avavee", donation: 5 }, - { id: 31, first_name: "Toni", last_name: "MacSweeney", email: "tmacsweeneyu@parallels.com", shirt_size: "M", company_name: "Jaloo", donation: 82 }, - { id: 32, first_name: "Jessey", last_name: "Walhedd", email: "jwalheddv@slashdot.org", shirt_size: "L", company_name: "Trilia", donation: 5 }, - { id: 33, first_name: "Karola", last_name: "Piper", email: "kpiperw@ucsd.edu", shirt_size: "3XL", company_name: "Yombu", donation: 110 }, - { id: 34, first_name: "Marley", last_name: "Mitchenson", email: "mmitchensonx@webeden.co.uk", shirt_size: "M", company_name: "Zoonoodle", donation: 97 }, - { id: 35, first_name: "Marrilee", last_name: "Thrasher", email: "mthrashery@opensource.org", shirt_size: "XL", company_name: "Bluejam", donation: 17 }, - { id: 36, first_name: "Tye", last_name: "Manie", email: "tmaniez@netscape.com", shirt_size: "L", company_name: "Kanoodle", donation: 30 }, - { id: 37, first_name: "Charleen", last_name: "Sheering", email: "csheering10@mit.edu", shirt_size: "3XL", company_name: "Jatri", donation: 262 }, - { id: 38, first_name: "Valma", last_name: "Eynaud", email: "veynaud11@archive.org", shirt_size: "XS", company_name: "Jaxbean", donation: 212 }, - { id: 39, first_name: "Dollie", last_name: "McDarmid", email: "dmcdarmid12@tinyurl.com", shirt_size: "S", company_name: "Kayveo", donation: 74 }, - { id: 40, first_name: "Minna", last_name: "Hymas", email: "mhymas13@cornell.edu", shirt_size: "XS", company_name: "Vimbo", donation: 101 }, - { id: 41, first_name: "Jsandye", last_name: "Frend", email: "jfrend14@ca.gov", shirt_size: "XS", company_name: "Latz", donation: 156 }, - { id: 42, first_name: "Yevette", last_name: "Hacket", email: "yhacket15@wp.com", shirt_size: "XL", company_name: "Lazzy", donation: 291 }, - { id: 43, first_name: "Hank", last_name: "Zebedee", email: "hzebedee16@ezinearticles.com", shirt_size: "L", company_name: "Gigashots", donation: 241 }, - { id: 44, first_name: "Jodie", last_name: "Stawell", email: "jstawell17@yale.edu", shirt_size: "S", company_name: "Jaxspan", donation: 262 }, - { id: 45, first_name: "Falito", last_name: "Karsh", email: "fkarsh18@pcworld.com", shirt_size: "S", company_name: "Mycat", donation: 239 }, - { id: 46, first_name: "Reginauld", last_name: "Purselowe", email: "rpurselowe19@thetimes.co.uk", shirt_size: "L", company_name: "Jabbersphere", donation: 11 }, - { id: 47, first_name: "Vida", last_name: "Tydd", email: "vtydd1a@dropbox.com", shirt_size: "S", company_name: "Quaxo", donation: 55 }, - { id: 48, first_name: "Anderea", last_name: "MacGiolla Pheadair", email: "amacgiollapheadair1b@xing.com", shirt_size: "2XL", company_name: "Kwimbee", donation: 214 }, - { id: 49, first_name: "Bel", last_name: "Alway", email: "balway1c@ow.ly", shirt_size: "S", company_name: "Voolia", donation: 107 }, - { id: 50, first_name: "Shell", last_name: "Baine", email: "sbaine1d@intel.com", shirt_size: "M", company_name: "Gabtype", donation: 171 }, + { + id: 1, + first_name: "Charmain", + last_name: "Seiler", + email: "cseiler0@wired.com", + shirt_size: "2XL", + company_name: "Divanoodle", + donation: 75 + }, + { + id: 2, + first_name: "Whitaker", + last_name: "Ierland", + email: "wierland1@angelfire.com", + shirt_size: "2XL", + company_name: "Wordtune", + donation: 148 + }, + { + id: 3, + first_name: "Julieta", + last_name: "McCloid", + email: "jmccloid2@yahoo.com", + shirt_size: "S", + company_name: "Riffpedia", + donation: 171 + }, + { + id: 4, + first_name: "Martynne", + last_name: "Paye", + email: "mpaye3@sciencedaily.com", + shirt_size: "XL", + company_name: "Wordware", + donation: 288 + }, + { + id: 5, + first_name: "Gussy", + last_name: "Raraty", + email: "graraty4@ucoz.ru", + shirt_size: "L", + company_name: "Oozz", + donation: 291 + }, + { + id: 6, + first_name: "Yule", + last_name: "Tommasetti", + email: "ytommasetti5@state.gov", + shirt_size: "S", + company_name: "Yodo", + donation: 27 + }, + { + id: 7, + first_name: "Kathie", + last_name: "Majury", + email: "kmajury6@guardian.co.uk", + shirt_size: "3XL", + company_name: "Zoomcast", + donation: 261 + }, + { + id: 8, + first_name: "Tanner", + last_name: "Branton", + email: "tbranton7@tmall.com", + shirt_size: "2XL", + company_name: "Realmix", + donation: 28 + }, + { + id: 9, + first_name: "Sarina", + last_name: "Lasham", + email: "slasham8@toplist.cz", + shirt_size: "XL", + company_name: "Gigashots", + donation: 110 + }, + { + id: 10, + first_name: "Bertie", + last_name: "Lonergan", + email: "blonergan9@issuu.com", + shirt_size: "3XL", + company_name: "Skinte", + donation: 62 + }, + { + id: 11, + first_name: "Trevor", + last_name: "Studd", + email: "tstudda@networkadvertising.org", + shirt_size: "S", + company_name: "Cogidoo", + donation: 76 + }, + { + id: 12, + first_name: "Malachi", + last_name: "Okeshott", + email: "mokeshottb@chron.com", + shirt_size: "M", + company_name: "DabZ", + donation: 91 + }, + { + id: 13, + first_name: "Berget", + last_name: "Logsdail", + email: "blogsdailc@wix.com", + shirt_size: "M", + company_name: "Mymm", + donation: 9 + }, + { + id: 14, + first_name: "Loise", + last_name: "Rivlin", + email: "lrivlind@behance.net", + shirt_size: "2XL", + company_name: "Linktype", + donation: 204 + }, + { + id: 15, + first_name: "Christan", + last_name: "Kendall", + email: "ckendalle@example.com", + shirt_size: "XS", + company_name: "Skinix", + donation: 252 + }, + { + id: 16, + first_name: "Kayla", + last_name: "Whitwam", + email: "kwhitwamf@deliciousdays.com", + shirt_size: "2XL", + company_name: "Oyope", + donation: 147 + }, + { + id: 17, + first_name: "Heddie", + last_name: "Heningam", + email: "hheningamg@tripadvisor.com", + shirt_size: "L", + company_name: "Skinix", + donation: 172 + }, + { + id: 18, + first_name: "Mace", + last_name: "Ballinger", + email: "mballingerh@a8.net", + shirt_size: "S", + company_name: "Nlounge", + donation: 266 + }, + { + id: 19, + first_name: "Nola", + last_name: "Abberley", + email: "nabberleyi@jalbum.net", + shirt_size: "XL", + company_name: "Photospace", + donation: 148 + }, + { + id: 20, + first_name: "Nadine", + last_name: "Tresler", + email: "ntreslerj@marketwatch.com", + shirt_size: "3XL", + company_name: "Wikido", + donation: 292 + }, + { + id: 21, + first_name: "Ulrikaumeko", + last_name: "Vuittet", + email: "uvuittetk@gov.uk", + shirt_size: "S", + company_name: "Skinte", + donation: 102 + }, + { + id: 22, + first_name: "Saunder", + last_name: "Spennock", + email: "sspennockl@icq.com", + shirt_size: "3XL", + company_name: "Kwimbee", + donation: 213 + }, + { + id: 23, + first_name: "Carmel", + last_name: "Woffinden", + email: "cwoffindenm@wikispaces.com", + shirt_size: "S", + company_name: "Rooxo", + donation: 137 + }, + { + id: 24, + first_name: "Marielle", + last_name: "Kimmel", + email: "mkimmeln@jimdo.com", + shirt_size: "M", + company_name: "Livetube", + donation: 96 + }, + { + id: 25, + first_name: "Brucie", + last_name: "Burris", + email: "bburriso@slate.com", + shirt_size: "2XL", + company_name: "Wordtune", + donation: 128 + }, + { + id: 26, + first_name: "Juan", + last_name: "Berzon", + email: "jberzonp@soup.io", + shirt_size: "3XL", + company_name: "Einti", + donation: 234 + }, + { + id: 27, + first_name: "Sacha", + last_name: "Olsen", + email: "solsenq@reverbnation.com", + shirt_size: "2XL", + company_name: "Viva", + donation: 190 + }, + { + id: 28, + first_name: "Jamey", + last_name: "O'Nolan", + email: "jonolanr@samsung.com", + shirt_size: "XL", + company_name: "Skinix", + donation: 31 + }, + { + id: 29, + first_name: "Morrie", + last_name: "Rainard", + email: "mrainards@yale.edu", + shirt_size: "XS", + company_name: "Podcat", + donation: 52 + }, + { + id: 30, + first_name: "Fidel", + last_name: "Roskelly", + email: "froskellyt@ibm.com", + shirt_size: "XS", + company_name: "Avavee", + donation: 5 + }, + { + id: 31, + first_name: "Toni", + last_name: "MacSweeney", + email: "tmacsweeneyu@parallels.com", + shirt_size: "M", + company_name: "Jaloo", + donation: 82 + }, + { + id: 32, + first_name: "Jessey", + last_name: "Walhedd", + email: "jwalheddv@slashdot.org", + shirt_size: "L", + company_name: "Trilia", + donation: 5 + }, + { + id: 33, + first_name: "Karola", + last_name: "Piper", + email: "kpiperw@ucsd.edu", + shirt_size: "3XL", + company_name: "Yombu", + donation: 110 + }, + { + id: 34, + first_name: "Marley", + last_name: "Mitchenson", + email: "mmitchensonx@webeden.co.uk", + shirt_size: "M", + company_name: "Zoonoodle", + donation: 97 + }, + { + id: 35, + first_name: "Marrilee", + last_name: "Thrasher", + email: "mthrashery@opensource.org", + shirt_size: "XL", + company_name: "Bluejam", + donation: 17 + }, + { + id: 36, + first_name: "Tye", + last_name: "Manie", + email: "tmaniez@netscape.com", + shirt_size: "L", + company_name: "Kanoodle", + donation: 30 + }, + { + id: 37, + first_name: "Charleen", + last_name: "Sheering", + email: "csheering10@mit.edu", + shirt_size: "3XL", + company_name: "Jatri", + donation: 262 + }, + { + id: 38, + first_name: "Valma", + last_name: "Eynaud", + email: "veynaud11@archive.org", + shirt_size: "XS", + company_name: "Jaxbean", + donation: 212 + }, + { + id: 39, + first_name: "Dollie", + last_name: "McDarmid", + email: "dmcdarmid12@tinyurl.com", + shirt_size: "S", + company_name: "Kayveo", + donation: 74 + }, + { + id: 40, + first_name: "Minna", + last_name: "Hymas", + email: "mhymas13@cornell.edu", + shirt_size: "XS", + company_name: "Vimbo", + donation: 101 + }, + { + id: 41, + first_name: "Jsandye", + last_name: "Frend", + email: "jfrend14@ca.gov", + shirt_size: "XS", + company_name: "Latz", + donation: 156 + }, + { + id: 42, + first_name: "Yevette", + last_name: "Hacket", + email: "yhacket15@wp.com", + shirt_size: "XL", + company_name: "Lazzy", + donation: 291 + }, + { + id: 43, + first_name: "Hank", + last_name: "Zebedee", + email: "hzebedee16@ezinearticles.com", + shirt_size: "L", + company_name: "Gigashots", + donation: 241 + }, + { + id: 44, + first_name: "Jodie", + last_name: "Stawell", + email: "jstawell17@yale.edu", + shirt_size: "S", + company_name: "Jaxspan", + donation: 262 + }, + { + id: 45, + first_name: "Falito", + last_name: "Karsh", + email: "fkarsh18@pcworld.com", + shirt_size: "S", + company_name: "Mycat", + donation: 239 + }, + { + id: 46, + first_name: "Reginauld", + last_name: "Purselowe", + email: "rpurselowe19@thetimes.co.uk", + shirt_size: "L", + company_name: "Jabbersphere", + donation: 11 + }, + { + id: 47, + first_name: "Vida", + last_name: "Tydd", + email: "vtydd1a@dropbox.com", + shirt_size: "S", + company_name: "Quaxo", + donation: 55 + }, + { + id: 48, + first_name: "Anderea", + last_name: "MacGiolla Pheadair", + email: "amacgiollapheadair1b@xing.com", + shirt_size: "2XL", + company_name: "Kwimbee", + donation: 214 + }, + { + id: 49, + first_name: "Bel", + last_name: "Alway", + email: "balway1c@ow.ly", + shirt_size: "S", + company_name: "Voolia", + donation: 107 + }, + { + id: 50, + first_name: "Shell", + last_name: "Baine", + email: "sbaine1d@intel.com", + shirt_size: "M", + company_name: "Gabtype", + donation: 171 + } ]; -// ==== 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 and populate a new array called `fullNames`. This array will contain just strings. +//* ==== 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 and populate a new array called `fullNames`. This array will contain just strings. let fullNames = []; +runners.forEach(runner => { + fullNames.push(`${runner.first_name} ${runner.last_name}`); +}); console.log(fullNames); -// ==== Challenge 2: Use .map() ==== -// The event director needs to have all the runners' first names in uppercase because the director BECAME DRUNK WITH POWER. Populate an array called `firstNamesAllCaps`. This array will contain just strings. +//* ==== Challenge 2: Use .map() ==== +//* The event director needs to have all the runners' first names in uppercase because the director BECAME DRUNK WITH POWER. Populate an array called `firstNamesAllCaps`. This array will contain just strings. let firstNamesAllCaps = []; +firstNamesAllCaps = runners.map(runner => { + return `${runner.first_name.toUpperCase()} ${runner.last_name}`; +}); console.log(firstNamesAllCaps); -// ==== Challenge 3: Use .filter() ==== -// The large shirts won't be available for the event due to an ordering issue. We need a filtered version of the runners array, containing only those runners with large sized shirts so they can choose a different size. This will be an array of objects. +//* ==== Challenge 3: Use .filter() ==== +//* The large shirts won't be available for the event due to an ordering issue. We need a filtered version of the runners array, containing only those runners with large sized shirts so they can choose a different size. This will be an array of objects. let runnersLargeSizeShirt = []; +runnersLargeSizeShirt = runners.filter(runner => { + if (runner.shirt_size === "L") { + return runner; + } +}); console.log(runnersLargeSizeShirt); -// ==== Challenge 4: Use .reduce() ==== -// The donations need to be tallied up and reported for tax purposes. Add up all the donations and save the total into a ticketPriceTotal variable. -let ticketPriceTotal = 0; +//* ==== Challenge 4: Use .reduce() ==== +//* The donations need to be tallied up and reported for tax purposes. Add up all the donations and save the total into a ticketPriceTotal variable. +let ticketPriceTotal = runners.reduce( + (acc, runner) => (acc += runner.donation), + 0 +); console.log(ticketPriceTotal); -// ==== Challenge 5: Be Creative ==== -// Now that you have used .forEach(), .map(), .filter(), and .reduce(). I want you to think of potential problems you could solve given the data set and the 5k fun run theme. Try to create and then solve 3 unique problems using one or many of the array methods listed above. +//* ==== Challenge 5: Be Creative ==== +//* Now that you have used .forEach(), .map(), .filter(), and .reduce(). I want you to think of potential problems you could solve given the data set and the 5k fun run theme. Try to create and then solve 3 unique problems using one or many of the array methods listed above. -// Problem 1 +//* Problem 1 +let totalDonations = runners.pop((acc, runner) => (acc += runner.donation), 0); +let averageDonation = totalDonations / runners.length; +console.log(averageDonation); -// Problem 2 +//* Problem 2 +function sortByDonation(arr, direction) { + switch (direction()) { + case "asc": { + return arr.sort((a, b) => { + return a.donation < b.donation ? -1 : 1; + }); + } + case "desc": { + return arr.sort((a, b) => { + return a.donation < b.donation ? 1 : -1; + }); + } + default: { + return "Yeet"; + } + } +} -// Problem 3 \ No newline at end of file +function sortAscending() { + return "asc"; +} + +function sortDescending() { + return "desc"; +} + +console.table(sortByDonation(runners, sortAscending)); + +//* Problem 3 +let emailList = []; + +runners.forEach(runner => { + emailList.push(runner.email); +}); + +console.log(emailList); diff --git a/assignments/callbacks.js b/assignments/callbacks.js index cb72e70c9..805a339ef 100644 --- a/assignments/callbacks.js +++ b/assignments/callbacks.js @@ -1,6 +1,6 @@ // Create a higher order function and invoke the callback function to test your work. You have been provided an example of a problem and a solution to see how this works with our items array. Study both the problem and the solution to figure out the rest of the problems. -const items = ['Pencil', 'Notebook', 'yo-yo', 'Gum']; +const items = ["Pencil", "Notebook", "yo-yo", "Gum"]; /* @@ -38,27 +38,36 @@ const items = ['Pencil', 'Notebook', 'yo-yo', 'Gum']; console.log(test2); // "this Pencil is worth a million dollars!" */ - function getLength(arr, cb) { // getLength passes the length of the array into the callback. + return cb(arr.length); } +getLength(items, result => console.log(result)); function last(arr, cb) { // last passes the last item of the array into the callback. + return cb(arr[arr.length - 1]); } +last(items, result => console.log(result)); function sumNums(x, y, cb) { // sumNums adds two numbers (x, y) and passes the result to the callback. + return cb(x + y); } +sumNums(10, 10, result => console.log(result)); function multiplyNums(x, y, cb) { // multiplyNums multiplies two numbers and passes the result to the callback. + return cb(x * y); } +multiplyNums(2, 4, result => console.log(result)); 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(list.includes(item)); } +contains("Gum", items, result => console.log(result)); /* STRETCH PROBLEM */ diff --git a/assignments/closure.js b/assignments/closure.js index 4b399c098..2dccbbd7e 100644 --- a/assignments/closure.js +++ b/assignments/closure.js @@ -1,33 +1,71 @@ -// ==== Challenge 1: Write your own closure ==== -// Write a closure of your own creation. -// Keep it simple! Remember a closure is just a function -// that manipulates variables defined in the outer scope. -// The outer scope can be a parent function, or the top level of the script. +//* ==== Challenge 1: Write your own closure ==== +//* Write a closure of your own creation. +//* Keep it simple! Remember a closure is just a function +//* that manipulates variables defined in the outer scope. +//* The outer scope can be a parent function, or the top level of the script. +const outerFunc = a => { + let num = a; + return (innerFunc = b => { + return (num += b); + }); +}; /* STRETCH PROBLEMS, Do not attempt until you have completed all previous tasks for today's project files */ - -// ==== Challenge 2: Implement a "counter maker" function ==== +//* ==== Challenge 2: Implement a "counter maker" function ==== +//* IMPLEMENTATION OF counterMaker: +//* 1- Declare a `count` variable with a value of 0. We will be mutating it, so declare it using `let`! +//* 2- Declare a function `counter`. It should increment and return `count`. +//* NOTE: This `counter` function, being nested inside `counterMaker`, +//* "closes over" the `count` variable. It can "see" it in the parent scope! +//* 3- Return the `counter` function. const counterMaker = () => { - // IMPLEMENTATION OF counterMaker: - // 1- Declare a `count` variable with a value of 0. We will be mutating it, so declare it using `let`! - // 2- Declare a function `counter`. It should increment and return `count`. - // NOTE: This `counter` function, being nested inside `counterMaker`, - // "closes over" the `count` variable. It can "see" it in the parent scope! - // 3- Return the `counter` function. + let count = 0; + return function counter() { + return count++; + }; }; -// Example usage: const myCounter = counterMaker(); -// myCounter(); // 1 -// myCounter(); // 2 -// ==== Challenge 3: Make `counterMaker` more sophisticated ==== -// It should have a `limit` parameter. Any counters we make with `counterMaker` -// will refuse to go over the limit, and start back at 1. +//* ==== Challenge 3: Make `counterMaker` more sophisticated ==== +//* It should have a `limit` parameter. Any counters we make with `counterMaker` +//* will refuse to go over the limit, and start back at 1. +const counterMakerSophisticated = limit => { + let count = 0; + let maxCount = limit; + + return function counter() { + if (count > maxCount) { + count = 1; + return count; + } else { + return count++; + } + }; +}; -// ==== Challenge 4: Create a counter function with an object that can increment and decrement ==== +//* ==== Challenge 4: Create a counter function with an object that can increment and decrement ==== const counterFactory = () => { - // 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. + 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 niceCounter = counterFactory(); +console.log(niceCounter.decrement()); +console.log(niceCounter.decrement()); +console.log(niceCounter.decrement()); +console.log(niceCounter.increment()); +console.log(niceCounter.increment()); +console.log(niceCounter.decrement()); +console.log(niceCounter.increment());