循环案例
<!DOCTYPE html>
<html>
<head>
<title>js开始学习</title>
<script>
var time = prompt('请你输入现在的时间段');
if (time >= 0 && time <= 12) {
alert('中午好');
} else if (time > 12 && time <= 18) {
alert('傍晚好');
} else {
alert('深夜好,该吃夜宵啦');
}
</script>
</head>
<body>
</body>
</html>
for 循环
<!DOCTYPE html>
<html>
<head>
<title>js开始学习</title>
<script>
for (var i = 1; i <= 100; i++) {
console.log('继续学习JavaScript');
}
for (var number = 1; number <= 10; number++) {
if (number == 1) {
console.log('从一开始计数');
} else if (number == 10) {
console.log('到末尾啦');
} else {
console.log('当中输出的数字为:' + number);
}
}
</script>
</head>
<body>
</body>
</html>
for 循环案例
<!DOCTYPE html>
<html>
<head>
<title>js开始学习</title>
<script>
var sum = 0;
for (var i = 1; i <= 100; i++) {
sum += i;
}
console.log(sum / 100);
var singleNum = 0,
doubleNum = 0;
for (var i = 1; i <= 100; i++) {
if (i % 2 == 0) {
doubleNum += i;
} else {
singleNum += i;
}
}
console.log('奇数和为:' + singleNum);
console.log('偶数和为:' + doubleNum);
var trippleNum = 0;
for (var i = 1; i <= 100; i++) {
if (i % 3 == 0) {
trippleNum += i;
}
}
console.log('能被3整除的数和为:' + trippleNum);
</script>
</head>
<body>
</body>
</html>
for 循环案例之求学生平均成绩
<!DOCTYPE html>
<html>
<head>
<title>js开始学习</title>
<script>
var total = prompt('请输入班级的总人数');
var grade = 0;
var totalGrade = 0;
for (var i = 1; i <= total; i++) {
grade = prompt('请输入第' + i + '个同学的成绩');
totalGrade += parseInt(grade);
}
averageGrade = totalGrade / parseInt(total);
alert('全班的平均成绩为:' + averageGrade);
</script>
</head>
<body>
</body>
</html>
for循环案例之打印星星
<!DOCTYPE html>
<html>
<head>
<title>js开始学习</title>
<script>
var number = prompt('请输入你想要打印的星星行数:');
var str = '';
for (var i = 1; i <= parseInt(number); i++) {
for (var j = 1; j <= parseInt(number); j++) {
str += '*';
}
str = str + '\n';
}
console.log(str);
</script>
</head>
<body>
</body>
</html>
for循环案例之打印倒三角星星
<!DOCTYPE html>
<html>
<head>
<title>js开始学习</title>
<script>
var num = prompt('请输入你想要打印的星星行数:');
var str = '';
for (var i = 1; i <= parseInt(num); i++) {
for (var j = 1; j <= parseInt(num) - i + 1; j++) {
str += '*';
}
str += '\n';
}
console.log(str);
</script>
</head>
<body>
</body>
</html>
for循环案例之打印九九乘法表
<!DOCTYPE html>
<html>
<head>
<title>js开始学习</title>
<script>
var num = '';
for (var i = 1; i <= 9; i++) {
for (var j = 1; j <= i; j++) {
num += j + 'x' + i + '=' + i * j + ' ';
}
num += '\n'
}
console.log(num);
</script>
</head>
<body>
</body>
</html>
for循环案例之简易ATM
<!DOCTYPE html>
<html>
<head>
<title>js开始学习</title>
<script>
var number = prompt('请输入您要的操作:\n1.存钱\n2.取钱\n3.显示余额\n4.退出');
var account = 100;
var testOne = 0;
if (number == 1) {
var num1 = prompt('请输入您要存的钱:');
account += parseInt(num1);
alert('您当前的余额为:' + account);
} else if (number == 2) {
var num2 = prompt('请输入您要取的钱:');
account -= parseInt(num2);
alert('您当前的余额为:' + account);
} else if (number == 3) {
alert('您当前的余额为:' + account);
} else {
testOne++;
alert('您正在退出,感谢使用！！');
}
</script>
</head>
<body>
</body>
</html>