First commit

index.js

@@ -0,0 +1,149 @@
+//1
+let a1 = () => alert('Привет')
+
+//2
+
+let b1 = (b) => b = b ** 3
+
+//3
+
+let c1 = (a, b) => (a + b) / 2
+
+//4
+
+let d1 = (a = 0, b = 0, c = 0) => g = a + b + c
+
+//5
+
+let e1 = (a, b) => {
+    if (b === undefined) {
+        z = Math.round(Math.random()*a) 
+    } else {
+        z =   ((Math.round(Math.random() * (b - a))+a))
+    }
+      return z
+}
+
+//6
+let p = ""
+let f1 = (...arguments) => {
+    
+    for (i = 0; i < arguments.length; i++){
+        p = p + "," + arguments[i] 
+        
+    }
+    
+    alert(`Hello ${p}`)
+}
+
+//7
+let sum1 = 0
+let g1 = (...arguments) => {
+    for (i = 0; i < arguments.length; i++){
+        sum1 += arguments[i]
+    }
+    return sum1
+}
+
+
+//sort
+
+var persons = [
+    {name: "Иван", age: 17},
+    {name: "Мария", age: 35},
+    {name: "Алексей", age: 73},
+    {name: "Яков", age: 12},
+]
+
+
+function sort1(array, key, bool = true) {
+     
+    if (bool) {
+        array.sort((a, b) => a[key] > b[key] ? 1 : -1)
+    }
+    else {
+        array.sort((a, b) => a[key] < b[key] ? 1 : -1)
+        return console.log(array)
+    }
+}   
+
+//sort(persons, "age"); //сортирует по возрасту по возрастанию
+sort1(persons, "name", false); //сортирует по имени по убыванию
+
+//array map
+
+["1", {}, null, undefined, "500", 700].map(x => typeof(x) === 'string' ? parseInt(x) : x)
+
+//array reduce
+    
+["0", 5, 3, "string", null].reduce(f)
+
+function f(a, b) {
+
+
+    if (typeof (a) === 'number' ) {
+        a = a
+    } else {
+        a = 1
+    }
+    if (typeof (b) === 'number') {
+        b = b
+    } else {
+        b = 1
+    }
+    return a * b
+
+}
+
+//object filter
+
+var phone = {
+    brand: "meizu",
+    model: "m2",
+    ram: 2,
+    color: "black",
+};
+
+function filter(object , search ,value) {
+    for (let key in object) {
+        if (key != search & object[key] != value)
+            delete object[key];
+
+           
+        }
+        return phone
+}
+
+filter(phone, "color", 2)
+
+//object map ????????
+
+function map(obj, funct){
+    for(key in obj){
+        funct(obj, key, obj[key]);
+        delete obj[key];
+    }
+    return obj;
+}
+
+function by(obj, key, value){
+    obj[key + "_"] = value + "$";
+    return obj;
+}
+console.log(map({ name: "Иван", age: 18, tel: 16780 }, by))
+
+
+//Sum
+
+function sum(a){
+    if (a === 1){
+        return a
+    }
+    else {
+        return a + sum(a - 1)
+    }
+
+    
+}
+
+