Function isObject

vue.js:66–69

* Quick object check - this is primarily used to tell * Objects from primitive values when we know the value * is a JSON-compliant type.

(obj)

     * is a JSON-compliant type.
     */
    function isObject(obj) {
        //判断是否是对象
        return obj !== null && typeof obj === 'object'
    }

    /**
     * Get the raw type string of a value e.g. [object Object]