find
var todo = todos.find(function(x) { return x.id === id; }); <script> const one = [30, 59, 48, 62, 105]; /*求和one 使用方法reduce*/ (function add() { var two = one.reduce(function (first, second) { return first + second }, 0); console.log(two); })(); /*筛选 filter*/ (function () { var todos = [ {text: '测试1', done: true}, {text: '测试2', done: false} ]; var data = todos.filter(function (p1) { return p1.done } ) console.log(data) })(); /*求平举值*/ function average() { var two = one.reduce(function (first, second) { return first + second }, 0); var len = one.length; var average = two / len; console.log(average); } /* 每个元素+10+索引*/ function add() { one.forEach(function (p1, p2, p3) { p3[p2] = p1 + 10 + p2 }); console.log(one) } /*元素转换成负数*/ function negative() { one.forEach(function (p1, p2, p3) { p3[p2] = -p1 }); console.log(one) } /*留下奇数*/ function odd() { var two = one.filter(function (item) { return item % 2 == 1 }); console.log(two) } /*整除3*/ function odd3() { var two = one.filter(function (item) { return item % 3 == 0 }); console.log(two) } /*1-100*/ function hundred() { var two=[...one.keys()]; console.log(two); var arr = [...new Array(100).keys()]; console.log(arr); console.log(Array.from(arr)); } /* * * 中文数组：[京东, 淘宝, 当当, 苏宁, 1号店] IE内核 * 按照拼音排序 * */ function pinyin() { var zz=['京东', '淘宝', '当当', '苏宁', '1号店'] console.log(zz.sort(function (a, b) { return a.localeCompare(b); })) } /*日期排序*/ function day() { var date=[new Date('2016-10-31'), '2016-1-1', '2014-5-29', '2019-3-28', '2001-2-6'] var end=date.sort(function (a,b) { return b.localeCompare(a) }); console.log(end) } /*对象输出key=value*/ function kequalv() { var kv= {name: 'John', age: 32, email: 'john@85ido.com', sex: 1 } for(var k in kv){ if (kv.hasOwnProperty(k)) { console.log(k+'='+kv[k]) } } Object.keys(kv).forEach(x => console.log(`${x} = ${kv[x]}`)); } kequalv() </script>