How to check if the JSON data is one object or an

问题:

I got server responsed JSON data:

var data = SERVER_RESPONSE;

this data could be an object {id: 12, name: John},

it could also be an array of objects [{id: 12, name: John}, {id: 22, name: OMG}]

In Javascript, how can I check if the JSON data is one object or an array of objects?

回答1:

You could use the following test:

if (data instanceof Array) {
    // data is an array
} else {
    // it is not an array
}

回答2:

A simple test is to check for the existence of obj.length and obj[0].

It's not 100% fool proof, but if you know that your data can only appear in one of the two formats you put in the question it should be sufficient.