一些方法

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>