HW<10.1> done

js/10.1-js-closures/main.js

@@ -0,0 +1,80 @@
+//makeProfileTimer
+function makeProfileTimer() {
+    let prev = performance.now();
+
+    return function () {
+        let next = performance.now();
+        return ("Время выполнения: " + (next - prev));
+    }
+}
+
+//makeSaver
+function makeSaver(el) {
+    let result;
+    let doFunc = true;
+
+    return function () {
+        if (doFunc) {
+            result = el();
+            doFunc = false;
+        }
+        return result;
+    }
+}
+
+var saver = makeSaver(Math.random);
+var value1 = saver();
+var value2 = saver();
+value1 === value2                 // true
+
+var saver2 = makeSaver(() => console.log('saved function called') || [null, undefined, false, '', 0, Math.random()][Math.ceil(Math.random() * 6)])
+var value3 = saver2()
+var value4 = saver2()
+
+value3 === value4 // тоже true
+
+
+//Final Countdown
+function finalCountdown(lastCountNumber) {              //параметр число с которого начинается обратный отсчёт
+    if (lastCountNumber >= 0) {
+        setTimeout((function () {
+            lastCountNumber === 0 ? console.log("поехали!") : console.log(lastCountNumber);
+
+            finalCountdown(lastCountNumber - 1);
+        }), 1000)
+    }
+}
+
+//myBind
+function myBind(func, context, ...args) {
+    let argsCopy = args;
+    argsCopy = argsCopy.flat();
+
+    return function (...args2) {
+        let j = 0;
+
+        for (let i = 0; i < argsCopy.length; i++) {
+            if (argsCopy[i] === undefined) {
+                argsCopy[i] = args2[j]
+                j++;
+            }
+        }
+        return func.call(context, ...argsCopy)
+    }
+}
+
+var pow5 = myBind(Math.pow, Math, [undefined, 5])
+var cube = myBind(Math.pow, Math, [undefined, 3])
+
+pow5(2) // => 32, вызывает Math.pow(2,5)
+cube(3) // => 27, вызывает Math.pow(3,3)
+
+
+var chessMin = myBind(Math.min, Math, [undefined, 4, undefined, 5, undefined, 8, undefined, 9])
+chessMin(-1, -5, 3, 15) // вызывает Math.min(-1, 4, -5, 5, 3, 8, 15, 9), результат -5
+
+var zeroPrompt = myBind(prompt, window, [undefined, "0"])
+var someNumber = zeroPrompt("Введите число")              // вызывает prompt("Введите число","0")
+
+myBind((...params) => params.join(''), null, [undefined, 'b', undefined, undefined, 'e', 'f'])('a', 'c', 'd') === 'abcdef' //true
+