函数的使用

1.函数的定义和使用:

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <title>if...else
        </title>
        <script type="text/javascript">
            var ticket = true;
            if (ticket) {
                document.write("有票,看电影")
            } else{
                document.write("没有票,看不了电影")
            }
            
            function add(a,b) {
                var sum = 0;
                sum = a + b;
                alert(sum);
            }
            add(4,3);
            add(2,4);
            alert(5,7);
        </script>
    </head>
    <body>
    </body>
</html>

2.函数的调用:

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>函数调用</title>
<script type="text/javascript">
function tcon()
  {
    alert("恭喜你学会函数调用了!");
  }
</script>
</head>
<body>
<form>
<input type="button"  value="点点我" onclick="tcon()">  
</form>
</body>
</html>

3.函数的返回值:

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>返回值函数</title>
<script type="text/javascript">
  function  app2(x,y)
  { var sum,x,y;
    sum = x * y;
    return sum;
  }
 var req1 = app2(5,6);
 var req2 = app2(2,3);
 var sumq = req1 + req2;
document.write("req1的值:"+req1+"<br/>");
document.write("req2的值:"+req2+"<br/>");
document.write(req1+"与"+req2+"和:"+sumq);
</script>
</head>
<body>
</body>
</html>

 

posted on 2017-02-04 21:03  玉思盈蝶  阅读(176)  评论(0)  编辑  收藏  举报

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