js练习作业

练习一：

代码：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        function analyzeGrades(arr1){
            let a = 0;
            let arr2 = [];
            for(let i = 0;i<arr1.length;i++){
                if(arr1[i]>0&&arr1[i]<100){
                    arr2[a] = arr1[i];
                    a++;
                }
            }
            let sum = 0;
            let pingjun = 0;
            for(let i = 0;i<arr2.length;i++){
                sum = sum + arr2[i];
            }
            pingjun = sum / arr2.length;
            for(let i=0;i<arr2.length-1;i++){
                for(let j=i+1;j<arr2.length;j++){
                    if(arr1[i]>arr1[j]){
                        n = arr2[i];
                        arr2[i] = arr2[j];
                        arr2[j] = n;
                    }
                }
            }
            document.writeln("<br>");
            document.writeln("总分为"+sum);
            document.writeln("<br>");
            document.writeln("平均分为"+pingjun.toFixed(2));
            document.writeln("<br>");
            document.writeln("最高分为"+arr2[arr2.length-1]);
            document.writeln("<br>");
            document.writeln("最低分为"+arr2[0]);
            let you = 0;
            let liang = 0;
            let zhong = 0;
            let cha = 0;
            for(let i = 0;i<arr2.length;i++){
                    if(arr2[i]<60){
                         cha++;
                    }
                    else if(arr2[i]>=60&&arr2[i]<80){
                         zhong++;
                    }
                    else if(arr2[i]>=80&&arr2[i]<90){
                         liang++;
                    }
                    else{
                         you++;
                    }
                }
            document.writeln("<br>");
            document.writeln("优有"+you+"人");
            document.writeln("<br>");
            document.writeln("良有"+liang+"人");
            document.writeln("<br>");
            document.writeln("中有"+zhong+"人");
            document.writeln("<br>");
            document.writeln("差有"+cha+"人");
        }
        let arr1 = [19,22,32,87,98,45,86,76,65,97,67,86,-100,101];
        analyzeGrades(arr1);
    </script>
</body>
</html>

结果截图：

第二题：

代码：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        function findPerfectNumbers(start, end){
            let arr = [];
            let b = 0;
            for(let i = start;i<=end;i++){
                let a = 0;
                for(let j = 1;j<i;j++){
                    if(i%j==0){
                        a = a + j;
                        }
                    }
                    if(a==i){
                        arr[b] = i;
                        b++;
                    }
                
            }
            return arr;
        }
        let arr = findPerfectNumbers(1,100);
        for(let i = 0;i<arr.length;i++){
            document.writeln(arr[i]);
        }
    </script>
</body>
</html>

结果截图：

第三题：

代码：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        function mergeArrays(arr1,arr2){
            let result = [];
            for(let i = 0;i<arr1.length;i++){
                result.push(arr1[i]);
            }
            let a = 0;
            for(let j = 0;j<arr2.length;j++){
                let x = false;
                for(let i = 0;i<arr1.length;i++){
                    if(arr2[j]==arr1[i]){
                        x = true;
                        break;
                    }
                }
                if(!x){
                    result.push(arr2[j]);
                }      
            }
            
            for(let i = 0;i<result.length;i++){
                document.writeln(result[i]);
            }
        }
        mergeArrays([1,2,3],[2,3,4,5]);
    </script>
</body>
</html>

结果截图：