第五周作业（JavaScript）
1.
<!DOCTYPE html>
<html lang="zh-CN">
<head><meta charset="utf-8" /><title>判断是否为整数</title><script>var n = 3.14;if (n%1==0){document.write(n+ "是整数")}else{document.write(n + "是小数")}</script>
</head>
<body>
</body>
</html>2.
<!DOCTYPE html>
<html lang="zh-CN">
<head><meta charset="utf-8" /><title>水仙花</title><script>var str = ""; for (var i = 100; i < 1000; i++){var a = i % 10; var b = (i / 10) % 10;b = parseInt(b); var c = i / 100; c = parseInt(c); if (i == (a * a * a + b * b * b + c * c * c)) {str = str + i + "、";}}document.write("水仙花数有：" + str);</script>
</head>
<body>
</body>
</html>3.
<!DOCTYPE html>
<html lang="zh-CN">
<head><meta charset="utf-8"/><title>判断是否为闰年</title><script>var a=2024;if((a%400==0)||(a%4==0&&a%100!=0))document.write(a+"是闰年");elsedocument.write(a+"不是闰年");</script>
</head>
</html>4.
<!DOCTYPE html>
<html lang="zh-CN">
<head><meta charset="utf-8"/><title>求出任意5个数的最大值</title><script>var arr=[5,2,3,6,4];var max=-99999;for(var i=0;i<arr.length;i++){if(max<arr[i])max=arr[i];}document.write("最大值是"+max);</script>
</head>
</html>5.
<!DOCTYPE html>
<html lang="zh-CN">
<head><meta charset="utf-8" /><title>统计某一个字符的个数</title><script>var str = "good good study,day day up";var n = 0;for(var i=0;i<str.length;i++){var char = str.charAt(i);if (char.toLowerCase() == "o") {n++;}}document.write("字符串中含有" + n + "个字母o");</script>
</head>
<body>
</body>
</html>6.
<!DOCTYPE html>
<html lang="zh-CN">
<head><meta charset="utf-8" /><title>统计字符串中有多少个数字</title><script>var str = "12aaaa 55bb5";var n = 0;for(var i=0;i<str.length;i++){var char = str.charAt(i);if (char!=0 && !isNaN(char)) {n++;}}document.write("字符串中含有" + n + "个数字");</script>
</head>
<body>
</body>
</html>7.
<!DOCTYPE html>
<html lang="zh-CN">
<head><meta charset="utf-8" /><title>数组与字符串的转换操作</title><script>var str1="我爱学习";var str2=str1.split("").join("><");var arr=str2.split("");arr.unshift("<");arr.push(">"); var result=arr.join("");document.write(result);</script>
</head>
<body>
</body>
</html>8.
<!DOCTYPE html>
<html lang="zh-CN">
<head><meta charset="utf-8" /><title>计算面积与体积，返回一个数组</title><script>function get(a,b,c){var S = 2*(a*b+a*c+b*c);var V = a*b*c;var arr=[S,V];return arr;}var a=get(1,2,3);document.write("表面积为"+a[0]+"<br/>");document.write("体积为"+a[1]);</script>
</head>
<body>
</body>
</html>9.
<!DOCTYPE html>
<html lang="zh-CN">
<head><meta charset="utf-8" /><title>显示时间</title><script>var d = new Date();var myYear=d.getFullYear();var myMonth=d.getMonth()+1;var myDay=d.getDate();var weekday=["日","一","二","三","四","五","六"];var myWeek=weekday[d.getDay()];document.write("今天是"+myYear+"年"+myMonth+"月"+myDay+"日"+" "+ "星期"+myWeek);</script>
</head>
<body>
</body>
</html>10.
<!DOCTYPE html>
<html lang="zh-CN">
<head><meta charset="utf-8" /><title>生成随机验证码</title><script>var str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";var arr = str.split("");var result = "";for(var i=0;i<4;i++){var n = Math.floor(Math.random() * arr.length);result += arr[n];}document.write(result);</script>
</head>
<body>
</body>
</html>11.
<!DOCTYPE html>
<html lang="zh-CN">
<head><meta charset="utf-8" /><title>生成随机颜色值</title><script>var r = Math.floor(Math.random() * (255 + 1));var g = Math.floor(Math.random() * (255 + 1));var b = Math.floor(Math.random() * (255 + 1));var rgb = "rgb(" + r + "," + g + "," + b + ")";document.write(rgb);</script>
</head>
<body>
</body>
</html>