Function 函数名(){
函数体；（代码块）
}
定义一个加法函数
<html> <head> <meta charset="utf-8 "> <meta name="generator" content="HTML Tidy for HTML5 (experimental) for Windows https://github.com/w3c/tidy-html5/tree/c63cc39" /> <title></title> </head> <body> <script>/* var a1=10; var a2=20; var sum=a1+a2; alert(sum);*/ function demo(a,b) { var sum=a+b; return sum; } var v1=demo(10,10); var v2=demo(20,10); var v3=demo(40,10); var v4=demo(60,10); alert(v1); alert(v2); alert(v3); alert(v4); </script> </body> </html>
带按钮的加法
<html> <head> <meta charset="utf-8" /> <meta name="generator" content="HTML Tidy for HTML5 (experimental) for Windows https://github.com/w3c/tidy-html5/tree/c63cc39" /> <title></title> </head> <body> <script> function demo(){ var a=10; var b=20; var sum=a+b; alert(sum); } </script><!-- <form><input type="button" value="按钮" onclick="demo()"/></form>--> <button onclick="demo()">按钮</button> </body> </html>
带参函数
<html> <head> <meta charset="utf-8" /> <meta name="generator" content="HTML Tidy for HTML5 (experimental) for Windows https://github.com/w3c/tidy-html5/tree/c63cc39" /> <title>函数</title> </head> <body> <script> function demo(a,b){ var sum=a+b; alert(sum);} demo(100,200); demo(10,20); </script> </body> </html>
两个按钮
<html> <head> <meta charset="utf-8" /> <meta name="generator" content="HTML Tidy for HTML5 (experimental) for Windows https://github.com/w3c/tidy-html5/tree/c63cc39" /> <title>函数</title> </head> <body> <script> function demo(name,age){ alert("hello"+name+",我的年龄是："+age); } </script> <button onclick="demo('iwen',20)">按钮</button> <button onclick="demo('iannn',25)">按钮</button> </body> </html>
