JS 数组试题训练

Array 数组

一些属性

.push（）//方法 往数组最后一位添加成员!
.unshift（）   // 往数组第一位添加成员!
.pop（）   //  将数组最后一位成员弹出!
.shift （）  // 将数组第一位成员弹出！
.join（） // 将数组转换成字符串!
.split（）// 将字符串重新生成数组！括号里面写分隔符（自定义的）；看字符串 
.reverse（） // 将数组成员倒序排列
.concat  （）//将两个数组进行合并！
.splice（1，2，3，4）//将数组中从下标为1的成员开始删除两个值 并在删除的位置添加3和4

一些实例

提取：http://www.jianshu.com?username=zhangshan&password=123456 该网址里面的 username 和 password 部分。

<script>
    
        var url1="http://www.jianshu.com?username=zhangsan&password=123456";
        var skr = url1.split("?"); //从“？”截取  获得新的数组有两个值
        console.log(skr)
        var sk2=skr[1];//获取下标为1的值
        var kkk=sk2.split("&");//在下标1的值，从“&”截取
        console.log(kkk)
        var t1=kkk[0];//获取kkk下标0的值
        var t2=kkk[1];//获取kkk下标1的值
        var user=t1.split("=");//从t1的“=”截取
        var pass=t2.split("=");//从t2的“=”截取
        document.write(user[1]);//渲染到页面user下标为1的值
        document.write("<br />")
        document.write(pass[1]);//渲染到页面pass下标为1的值
    var father = {
</script>

数组去重复！

<script>
    
        var arr = ["a","b","a","c","d","f","b","b","a","c","d","f","b","b","a","c","d","f","b","b","a","c","d","f","b","b","a","c","d","f","b","b","a","c","d","f","b","b","a","c","d","f","b","b","a","c","d","f","b","b","a","c","d","f","b","b","a","c","d","f","b","b","a","c","d","f","b"];
        var sum = [];
        var flag = true;
            for (var i in arr) {
                flag = true;
                for (var j in sum) {
                    if (arr[i] == sum[j]) {
                        flag = false;
                    }
                } if (flag) {
                    sum.push(arr[i]);
                }

            }
            document.write(sum);
    </script>

var math=["语文 = 99","数学 = 90","英语 = 88","历史 = 25","化学 = 30","生物 = 80","体育 = 99","物理 = 100","政治 = 70"]; 求最大最小平均分总分！

<script>
    var math=["语文=99","数学=90","英语=88","历史=25","化学=30","生物=80","体育=99","物理=100","政治=70"];
    var fenshu1 = [];
    var fenshu2 = [];
        for (var index in math) {
                var fenshu1 = math[index].split("=");
                fenshu2.push(parseInt(fenshu1[1]));
            }
            fenshu2.sort(daxiao);

            var sum = 0;
            for (var index in fenshu2) {
                sum += fenshu2[index];
            }
 document.write("最低分为:" + fenshu2[0] + "<br />" + "最高分为：" + fenshu2[8] + "<br />" + "平均分为：" + sum / 9 + "<br />" + "总分为：" + sum)

//函数大小定义
            function daxiao(a, b) {
                if (a > b) {
                    return 1;
                } else if (a == b) {
                    return 0;
                } else if (a < b) {
                    return -1;
                }

            }
    
    </script>