js题 - 运行结果

1，写出执行结果

var num1 = 55
    var num2 = 66
    function f1 (num, num1) {
        num = 100
        num1 = 100
        num2 = 100
        console.log(num)
        console.log(num1)
        console.log(num2)
    }
    f1(num1, num2)
    console.log(num1)
    console.log(num2)
    console.log(num)

image.png

2,写出执行结果

function Person (name, age, salary) {
        this.name = name
        this.age = age
        this.salary = salary
    }
    function f1 (person) {
        person.name = 'ls'
        person = new Person('aa', 18, 10)
    }
    var p = new Person('zs', 18, 1000)
    console.log(p.name)
    f1(p)
    console.log(p.name)

function Person (name, age, salary) {
        this.name = name
        this.age = age
        this.salary = salary
    }
    function f1 (person) {
        person.name = 'ls'
        person = new Person('aa', 18, 10)
    }
    var p = new Person('zs', 18, 1000)
    console.log(p.name)
    f1(p)
    console.log(p.name)
// 'zs'  'ls'

3，已知字符串foo = 'get-element-by-id'，写一个function将其转成驼峰表示法'getElementById'

    var foo = 'get-element-by-id'
    var arr = foo.split('-')   // split根据字符串进行切割 把字符串转成数组
    for (var i = 1; i < arr.length; i++) {
        arr[i] = arr[i].charAt(0).toUpperCase() + arr[i].substr(1, arr[i].length)
    }
    console.log(arr.join(''))   // getElementById   join('') 将数组转成字符串

对应方法:
    var foo = 'get-element-by-id'
    function toString(v) {
        var arr = v.split('-')
        for (var i = 1; i < arr.length; i++) {
            arr[i] = arr[i].charAt(0).toUpperCase() + arr[i].substr(1, arr[i].length)
        }
        console.log(arr.join(''))   // getElementById
        return arr
    }
    toString(foo)

4,反转数组 reverse

var arr = [1, 2, 3, 4, 5, 6, 7, 8]
    function reverse (v) {
        for (var i = 0; i < v.length / 2; i++) {
            var temp = arr[i]
            v[i] = arr[v.length - 1 - i]
            v[v.length - 1 - i] = temp
        }
        console.log(v)
        return v
    }
    reverse(arr)    // [8, 7, 6, 5, 4, 3, 2, 1]

5,去重
1,简单的去重

var arr = [8, 11, 20, 5, 20, 8, 0, 2, 4, 0, 8]
    function uniq (v) {
        var ary = []
        for (var i = 0; i < v.length; i++) {
            if (ary.indexOf(v[i]) === -1) {
                ary.push(v[i])
            }
        }
        console.log(ary)
        return ary
    }
    uniq(arr)