练习一:

代码:
html
<!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:
html
<!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:
html
<!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:
