| data.json |
Refer to: Using map and filter (not reduce) to get unique values of array (JavaScript).
[ 2019, 2018, 2017 ]) OR2019 and 2017);$ node ./index.js
$ docker run --rm -v $(pwd):/app -w /app node node index.js
| // npm i microtime benchmark | |
| var Benchmark = require('benchmark'); | |
| var suite = new Benchmark.Suite; | |
| var data = require("./data.json") | |
| suite.add("map+filter", function() { | |
| const result = data.map(record => { | |
| return record.period.split("-")[0] | |
| }).filter((elem, index, self) => { | |
| return index == self.indexOf(elem) | |
| }) | |
| }) | |
| .add("do+while", function() { | |
| if (data.length > 0) { | |
| let result = records.map(record => { | |
| return parseInt(record.period.split("-")[0]) | |
| }) | |
| let current | |
| let arr2 = [] | |
| do { | |
| current = result.pop() | |
| if (arr2.indexOf(current) == -1) { | |
| arr2.push(current) | |
| } | |
| } while (result.length > 0) | |
| return arr2 | |
| } else { | |
| return [] | |
| } | |
| }) | |
| .on("cycle", function(event) { | |
| console.log(String(event.target)); | |
| }) | |
| .on("complete", function() { | |
| console.log("Fastest is " + this.filter("fastest").map("name")); | |
| }) | |
| .run({ "async": true }); |
| function getYears(records) { | |
| if (records.length > 0) { | |
| let result = records.map(record => { | |
| return parseInt(record.period.split("-")[0]) | |
| }) | |
| let current | |
| let arr2 = [] | |
| do { | |
| current = result.pop() | |
| if (arr2.indexOf(current) == -1) { | |
| arr2.push(current) | |
| } | |
| } while (result.length > 0) | |
| return arr2 | |
| } else { | |
| return [] | |
| } | |
| } | |
| const data = [ | |
| { "period": "2019-02-01", value: "10" }, | |
| { "period": "2019-01-01", value: "1" }, | |
| { "period": "2018-01-01", value: "2" }, | |
| { "period": "2017-01-01", value: "3" }, | |
| ] | |
| console.log(getYears(data)) |
| const data = [ | |
| { "period": "2019-02-01", value: "10" }, | |
| { "period": "2019-01-01", value: "1" }, | |
| { "period": "2018-01-01", value: "2" }, | |
| { "period": "2017-01-01", value: "3" }, | |
| ] | |
| const result = data.map(record => { | |
| return record.period.split("-")[0] | |
| }).filter((elem, index, self) => { | |
| return index == self.indexOf(elem) | |
| }) | |
| console.log(result) |