实例 1制作一个成绩判断
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>javascript第一节课</title>
</head>
<body>
<script type="text/javascript">
var grade=80;
if (grade>=90&&grade<=100) {
alert('优秀');
}else if (grade>=80&&grade<=89) {
alert('良好');
}else if (grade>=70&&grade<=79){
alert('良');
}else if (grade>=60&&grade<=69){
alert('及格');
}else if(grade<=59){
alert('不及格');
}
</script>
</body>
</html>运行实例 »
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实例 判断闰年还是平年
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>javascript第一节课</title>
</head>
<body>
<script type="text/javascript">
var year=1888;
if (year%100 !==0&&year%400==0||year%4==0) {
alert('闰年');
}else{
alert('平年');
}
//也可以用一下方式计算
// var year = 2020;
// var isRun = year%4 == 0 && year%100 != 0 || year%400 ==0;
// console.log(isRun);
// if (isRun=true) {
// alert('闰年');
// }else{
// alert('平年');
// }
</script>
</body>
</html>运行实例 »
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