JavaScript一直让我惊讶，这是另一个例子。我只是遇到了一些代码，一开始我不理解。所以我对它进行了调试，得到了这样的发现:
alert('a'['toUpperCase']()); //alerts 'A'
现在，如果toUpperCase()被定义为string类型的成员，这肯定是显而易见的，但最初对我来说没有意义。
不管怎么说,
does this work because toUpperCase is a member of 'a'? Or there is something else going on behind the scenes? the code I was reading has a function as follows: function callMethod(method) { return function (obj) { return obj[method](); //**how can I be sure method will always be a member of obj** } } var caps2 = map(['a', 'b', 'c'], callMethod('toUpperCase')); // ['A','B','C'] // ignoring details of map() function which essentially calls methods on every // element of the array and forms another array of result and returns it It is kinda generic function to call ANY methods on ANY object. But does that mean the specified method will already be an implicit member of the specified object?
我确信我对JavaScript函数的基本概念缺少一些认真的理解。请帮助我理解这一点。
