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@@ -0,0 +1,105 @@
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+// sort
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+{
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+ var persons = [
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+ { name: "Иван", age: 17 },
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+ { name: "Мария", age: 35 },
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+ { name: "Алексей", age: 73 },
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+ { name: "Яков", age: 12 },
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+ ]
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+
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+ function sort(arr, type, bool = true) {
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+ return arr.sort((a, b) => {
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+ let result;
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+ if (bool) {
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+ console.log('true')
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+ result = a[type] > b[type] ? 1 : -1;
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+ } else {
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+ console.log('false')
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+ result = a[type] < b[[type]] ? 1 : -1;
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+ }
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+ return result
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+ })
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+ }
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+ console.log(sort(persons, 'name', false))
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+
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+}
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+
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+// array map
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+
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+{
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+ let arr = ["20", null, undefined, "5", {}, 700];
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+
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+ let arrMap = arr.map(function (item, index, arr) {
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+ let number = parseInt(item);
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+ return isNaN(number) ? item : number;
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+ });
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+
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+ console.log(arrMap);
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+}
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+
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+// array reduce
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+
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+{
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+ let arr = ["0", 5, 3, "string", null];
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+
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+ let result = arr.reduce(function (previousValue, currentValue) {
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+ if (typeof (currentValue) === 'number') {
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+ previousValue *= currentValue;
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+ };
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+ return previousValue
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+ }, 1)
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+ alert(result);
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+}
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+
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+// object filter
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+{
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+ let phone = {
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+ brand: "meizu",
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+ model: "m2",
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+ ram: 2,
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+ color: "black",
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+ };
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+
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+ function filter(object, func) {
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+ for (let key in object) {
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+ if (!func(key, object[key])) {
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+ delete object[key];
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+ }
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+ }
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+ return object;
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+ }
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+
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+ console.log(filter(phone, (key, value) => key == "color" || value == 2));
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+}
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+
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+// object map
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+{
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+ function map(object, func) {
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+ const fields = [];
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+ for (let key in object) {
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+ fields.push(func(key, object[key]));
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+ }
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+ return Object.assign({}, ...fields);
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+ }
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+ console.log(
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+ map({ name: "Иван", age: 17 }, function (key, value) {
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+ let result = {};
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+ result[key + "_"] = value + "$";
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+ return result;
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+ })
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+ );
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+}
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+
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+//sum recursion
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+{
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+ function sum(n) {
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+ if (n === 0) {
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+ return 0
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+ } else {
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+ return n + sum(n - 1);
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+ }
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+ }
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+
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+ console.log(sum(100));
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+
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+}
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