1 <!DOCTYPE html> 2 <html> 3 <head> 4 <meta charset="UTF-8"> 5 <title>js的方法重载</title> 6 <script type="text/javascript"> 7 // JavaScript不存在方法重载 8 // 通过arguments数组来模拟方法重载的效果 9 function add() { 10 var length = arguments.length; 11 var result; 12 switch (length) 13 { 14 case 2: 15 result = arguments[0] + arguments[1]; 16 break; 17 case 3: 18 result = arguments[0] + arguments[1] + arguments[2]; 19 break; 20 default: 21 result = -1; 22 break; 23 } 24 return result; 25 } 26 alert(add(1,2)); // 3 27 alert(add(1,2,3)); // 6 28 alert(add(1,2,3,4));// -1 29 </script> 30 </head> 31 <body> 32 33 </body> 34 </html>