added csbin closures

AlveeM · AlveeM · commit ad20e1715749 · 2021-06-08T19:19:50.000-04:00
diff --git a/csbin/closure/01-createFunction.js b/csbin/closure/01-createFunction.js
@@ -0,0 +1,8 @@
+function createFunction() {
+  return function() {
+    console.log("hello")
+  }
+}
+
+const function1 = createFunction();
+function1(); // => should console.log('hello');
diff --git a/csbin/closure/02-createFunctionPrinter.js b/csbin/closure/02-createFunctionPrinter.js
@@ -0,0 +1,10 @@
+function createFunctionPrinter(input) {
+  return function() {
+    console.log(input);
+  }
+}
+
+const printSample = createFunctionPrinter('sample');
+printSample(); // => should console.log('sample');
+const printHello = createFunctionPrinter('hello');
+printHello(); // => should console.log('hello');
diff --git a/csbin/closure/03-addByX.js b/csbin/closure/03-addByX.js
@@ -0,0 +1,42 @@
+function outer() {
+  let counter = 0; // this variable is outside incrementCounter's scope
+  function incrementCounter () {
+    counter ++;
+    console.log('counter', counter);
+  }
+  return incrementCounter;
+}
+
+const willCounter = outer();
+const jasCounter = outer();
+
+// Uncomment each of these lines one by one.
+// Before your do, guess what will be logged from each function call.
+
+// /*** Uncomment these to check your work! ***/
+// willCounter();
+// willCounter();
+// willCounter();
+
+// jasCounter();
+// willCounter();
+
+
+function addByX(x) {
+  return function(num) {
+    return num + x;
+  }
+}
+
+const addByTwo = addByX(2);
+console.log(addByTwo(1)); // => should return 3
+console.log(addByTwo(2)); // => should return 4
+console.log(addByTwo(3)); // => should return 5
+
+const addByThree = addByX(3);
+console.log(addByThree(1)); // => should return 4
+console.log(addByThree(2)); // => should return 5
+
+const addByFour = addByX(4);
+console.log(addByFour(4)); // => should return 8
+console.log(addByFour(5)); // => should return 9
diff --git a/csbin/closure/04-once.js b/csbin/closure/04-once.js
@@ -0,0 +1,17 @@
+function once(func) {
+  let called = false;
+  let res;
+  return function(val) {
+    if (!called) {
+      res = func(val);
+      called = true;
+    }
+    return res;
+  }
+}
+
+const addByTwo = num => num + 2;
+const onceFunc = once(addByTwo);
+console.log(onceFunc(4));  // => should log 6
+console.log(onceFunc(10));  // => should log 6
+console.log(onceFunc(9001));  // => should log 6
diff --git a/csbin/closure/05-after.js b/csbin/closure/05-after.js
@@ -0,0 +1,16 @@
+function after(count, func) {
+  let callCount = 1;
+  return function() {
+    if (callCount === count) {
+      func();
+    }
+    callCount++;
+  }
+}
+
+// /*** Uncomment these to check your work! ***/
+const called = function() { console.log('hello') };
+const afterCalled = after(3, called);
+afterCalled(); // => nothing is printed
+afterCalled(); // => nothing is printed
+afterCalled(); // => 'hello' is printed
diff --git a/csbin/closure/06-delay.js b/csbin/closure/06-delay.js
@@ -0,0 +1,5 @@
+function delay(func, wait, ...args) {
+  return function() {
+    setTimeout(() => func(...args), wait);
+  }
+}
diff --git a/csbin/closure/07-rollcall.js b/csbin/closure/07-rollcall.js
@@ -0,0 +1,17 @@
+function rollCall(names) {
+  i = 0;
+  return function() {
+    if (i >= names.length) {
+      console.log('Everyone accounted for');
+      return;
+    }
+    console.log(names[i]);
+    i++;
+  }
+}
+
+const rollCaller = rollCall(['Victoria', 'Juan', 'Ruth'])
+rollCaller() // => should log 'Victoria'
+rollCaller() // => should log 'Juan'
+rollCaller() // => should log 'Ruth'
+rollCaller() // => should log 'Everyone accounted for'
diff --git a/csbin/closure/08-saveOutput.js b/csbin/closure/08-saveOutput.js
@@ -0,0 +1,14 @@
+function saveOutput(func, magicWord) {
+  const tracker = {};
+  return function(val) {
+    if (val === magicWord) return tracker;
+    tracker[val] = func(val);
+    return tracker[val];
+  }
+}
+
+const multiplyBy2 = function(num) { return num * 2; };
+const multBy2AndLog = saveOutput(multiplyBy2, 'boo');
+console.log(multBy2AndLog(2)); // => should log 4
+console.log(multBy2AndLog(9)); // => should log 18
+console.log(multBy2AndLog('boo')); // => should log { 2: 4, 9: 18 }
diff --git a/csbin/closure/09-cycleIterator.js b/csbin/closure/09-cycleIterator.js
@@ -0,0 +1,19 @@
+function cycleIterator(array) {
+  let i = 0;
+  return function() {
+    const curEl = array[i];
+    if (i === array.length - 1) {
+      i = 0;
+      return curEl;
+    }
+    i++;
+    return curEl;
+  }
+}
+
+const threeDayWeekend = ['Fri', 'Sat', 'Sun'];
+const getDay = cycleIterator(threeDayWeekend);
+console.log(getDay()); // => should log 'Fri'
+console.log(getDay()); // => should log 'Sat'
+console.log(getDay()); // => should log 'Sun'
+console.log(getDay()); // => should log 'Fri'
diff --git a/csbin/closure/10-defineFirstArg.js b/csbin/closure/10-defineFirstArg.js
@@ -0,0 +1,9 @@
+function defineFirstArg(func, arg) {
+  return function(...args) {
+    return func(arg, ...args);
+  }
+}
+
+const subtract = function(big, small) { return big - small; };
+const subFrom20 = defineFirstArg(subtract, 20);
+console.log(subFrom20(5)); // => should log 15
diff --git a/csbin/closure/11-dateStamp.js b/csbin/closure/11-dateStamp.js
@@ -0,0 +1,12 @@
+function dateStamp(func) {
+  return function(...args) {
+      let today = new Date();
+      return {
+          date: today.toDateString(),
+          output: func(...args)
+      }
+  }
+}
+const stampedMultBy2 = dateStamp(n => n * 2);
+console.log(stampedMultBy2(4)); // => should log { date: (today's date), output: 8 }
+console.log(stampedMultBy2(6)); // => should log { date: (today's date), output: 12 }
diff --git a/csbin/closure/12-censor.js b/csbin/closure/12-censor.js
@@ -0,0 +1,18 @@
+function censor() {
+  const cache = {}
+  return function (str1, str2) {
+		if (str2) {
+    	cache[str1] = str2;
+  	} else {
+      Object.keys(cache).forEach(key => {
+        str1 = str1.replace(key, cache[key]);
+      })
+      return str1;
+    }
+  }
+}
+
+const changeScene = censor();
+changeScene('dogs', 'cats');
+changeScene('quick', 'slow');
+console.log(changeScene('The quick, brown fox jumps over the lazy dogs.')); // => should log 'The slow, brown fox jumps over the lazy cats.'
diff --git a/csbin/closure/13-createSecretHolder.js b/csbin/closure/13-createSecretHolder.js
@@ -0,0 +1,16 @@
+function createSecretHolder(secret) {
+  let secretVal = secret;
+  return{
+    getSecret() {
+      return secretVal;
+    },
+    setSecret(newSecret) {
+      secretVal = newSecret;
+    }
+  }
+}
+
+obj = createSecretHolder(5)
+console.log(obj.getSecret()) // => returns 5
+obj.setSecret(2)
+console.log(obj.getSecret()) // => returns 2
diff --git a/csbin/closure/14-callTimes.js b/csbin/closure/14-callTimes.js
@@ -0,0 +1,14 @@
+function callTimes() {
+  let numCalled = 0;
+  return function() {
+    numCalled++;
+    return numCalled;
+  }
+}
+
+let myNewFunc1 = callTimes();
+let myNewFunc2 = callTimes();
+console.log(myNewFunc1()); // => 1
+console.log(myNewFunc1()); // => 2
+console.log(myNewFunc2()); // => 1
+console.log(myNewFunc2()); // => 2
diff --git a/csbin/closure/15-russianRoulette.js b/csbin/closure/15-russianRoulette.js
@@ -0,0 +1,20 @@
+function russianRoulette(num) {
+  let timesCalled = 0;
+  return function() {
+    timesCalled++;
+    if (timesCalled === num) {
+      return 'bang';
+    } else if(timesCalled > num) {
+      return 'reload to play again';
+    } else {
+      return 'click';
+    }
+  }
+}
+
+const play = russianRoulette(3);
+console.log(play()); // => should log 'click'
+console.log(play()); // => should log 'click'
+console.log(play()); // => should log 'bang'
+console.log(play()); // => should log 'reload to play again'
+console.log(play()); // => should log 'reload to play again'
diff --git a/csbin/closure/16-average.js b/csbin/closure/16-average.js
@@ -0,0 +1,25 @@
+function average() {
+  const cache = {
+    avg: 0,
+    sum: 0,
+    count: 0
+  }
+  return function(num) {
+    if (num === undefined) {
+      return cache.avg;
+    } else {
+      cache.sum += num;
+      cache.count++;
+      cache.avg = cache.sum / cache.count;
+      return cache.avg;
+    }
+  }
+}
+
+const avgSoFar = average();
+console.log(avgSoFar()); // => should log 0
+console.log(avgSoFar(4)); // => should log 4
+console.log(avgSoFar(8)); // => should log 6
+console.log(avgSoFar()); // => should log 6
+console.log(avgSoFar(12)); // => should log 8
+console.log(avgSoFar()); // => should log 8
diff --git a/csbin/closure/17-makeFuncTester.js b/csbin/closure/17-makeFuncTester.js
@@ -0,0 +1,23 @@
+function makeFuncTester(arrOfTests) {
+  return function(func) {
+    for (let arr of arrOfTests) {
+      const arg = arr[0];
+      const res = arr[1];
+      if (func(arg) !== res) {
+        return false;
+      }
+    }
+    return true;
+  }  
+}
+
+// /*** Uncomment these to check your work! ***/
+const capLastTestCases = [];
+capLastTestCases.push(['hello', 'hellO']);
+capLastTestCases.push(['goodbye', 'goodbyE']);
+capLastTestCases.push(['howdy', 'howdY']);
+const shouldCapitalizeLast = makeFuncTester(capLastTestCases);
+const capLastAttempt1 = str => str.toUpperCase();
+const capLastAttempt2 = str => str.slice(0, -1) + str.slice(-1).toUpperCase();
+console.log(shouldCapitalizeLast(capLastAttempt1)); // => should log false
+console.log(shouldCapitalizeLast(capLastAttempt2)); // => should log true
diff --git a/csbin/closure/18-makeHistory.js b/csbin/closure/18-makeHistory.js
@@ -0,0 +1,26 @@
+function makeHistory(limit) {
+	let history = [];
+  return function (input) {
+    if (input === 'undo') {
+      if (history.length === 0) return 'nothing to undo';
+      const lastWord = history.pop();
+      return `${lastWord} undone`;s
+    } 
+    history.push(input);
+    if (history.length > limit) {
+      history = history.slice(1);
+    }
+		return `${input} done`;
+  }
+}
+
+// /*** Uncomment these to check your work! ***/
+const myActions = makeHistory(2);
+console.log(myActions('jump')); // => should log 'jump done'
+console.log(myActions('undo')); // => should log 'jump undone'
+console.log(myActions('walk')); // => should log 'walk done'
+console.log(myActions('code')); // => should log 'code done'
+console.log(myActions('pose')); // => should log 'pose done'
+console.log(myActions('undo')); // => should log 'pose undone'
+console.log(myActions('undo')); // => should log 'code undone'
+console.log(myActions('undo')); // => should log 'nothing to undo'
diff --git a/csbin/closure/19-blackjack.js b/csbin/closure/19-blackjack.js
