I've been tinkering with objects and seemingly you can have '' (an empty string) as a property name, like so:
o = {
'': 'hello',
1: 'world',
'abc': ':-)',
};
console.log(o['']);
似乎工作得很好，但我很好奇地想知道，is this really valid?我戳了戳ECMA规范，问了我们知识渊博的朋友谷歌这个问题的变体，我的结论是I don't know.
My sources
Yes, technically its totally valid and you can safely use it. An object key needs to be a "string", which does not exclude an empty string.
If that is convenient or even useful is another story.
见Should I use an empty property key?
Since the 'empty string' is one of the falsy values in ecmascript, consider the following example:
var foo = {
':-)': 'face',
'answer': 42,
'': 'empty'
};
Object.keys( foo ).forEach(function( key ) {
if( key ) {
console.log(key);
}
});
That snippet would only log :-) and answer. So that is one pitfall for doing this.