JavaS/ex10.html at master · JanikOskar/JavaS · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
<DOCTYPE! html>
  <html>

  <head>
    <meta charset="UTF-8" ; />
    <title>Exercise 10</title>
  </head>

  <body>
    <button onclick="myFunction()">Try it</button>
    <p id="demo"></p>
    <script>
      function myFunction() {
        var year = Number(prompt("enter a year"));
        var counter = 20;

        function leapyear(years, num) {
          years = parseInt(years);
          var origNum = num;
          years++;
          var leapYears = "";
          while (num > 0) {
            if (
              years % 4 === 0 &&
              (years % 100 !== 0 || (years % 100 === 0 && years % 400 === 0))
            ) {
              if (num === 1) {
                leapYears += years + ".";
              } else {
                leapYears += years + ", ";
              }
              years++;
              num--;
            } else {
              years++;
            }
          }
          return "The next " + origNum + " leap years are " + leapYears;
        }

        document.write(leapyear(year, counter));
      }
    </script>
  </body>

  </html>
</DOCTYPE!>