<!doctype html> <html> <head> <title> call - apply for inherit </title> </head> <body> <script type="text/javascript"> function baseA() // base Class A { this.member = "baseA member"; this.showSelfA = function() { window.alert(this.member); } } function baseB() // base Class B { this.member = "baseB member"; this.showSelfB = function() { window.alert(this.member); } } function extendAB() // Inherit Class from A and B { baseA.call(this); // call for A baseB.call(this); // call for B } window.onload = function() { var extend = new extendAB(); extend.showSelfA(); // show A extend.showSelfB(); // show B } </script> </body> </html>
运行结果如下：
baseB member
baseB member
测试环境：Google Chrome
结果分析：
预期的结果，应该是输出 baseA member 和 baseB member，但实际输出却是 baseB member 和 baseB member
以这种方式去实现所谓的多继承，结果：相同的变量会被覆盖；
当然，我们也可以对上面baseA代码稍作修改，来验证我们调试分析的正确性：
function baseA() // base Class A { this.memberA = "baseA member"; // member改成memberA，以区分baseB中的member this.showSelfA = function() { window.alert(this.memberA); // 显示memberA } }