使用对象替换switch语句

Question

I found the following exemple on the jqfundamentals site. It seems to me that the else statement is unnecessary/wrong. So what am I missing ?

var stuffToDo = {
    'bar' : function() {
        alert('the value was bar -- yay!');
    },

    'baz' : function() {
        alert('boo baz :(');
    },

    'default' : function() {
        alert('everything else is just ok');
    }
};

if (stuffToDo[foo]) {
    stuffToDo[foo]();
} else {
    stuffToDo['default']();
}

Answer 1

It's just checking that stuffToDo[foo] exists...

and If it doesn't call the 'default'

Not sure that I think replacing the switch statement is necessary or good, let alone a fundamental of javascript...

Answer 2

如果foo是"moo" ，则将stuffToDo['default']() （以避免引发异常）。