/**
         * Returns true if the passed value is empty, false otherwise. The value is deemed to be empty if it is either:
         *
         * - `null`
         * - `undefined`
         * - a zero-length array
         * - a zero-length string (Unless the `allowEmptyString` parameter is set to `true`)
         *
         * @param {Object} value The value to test
         * @param {Boolean} allowEmptyString (optional) true to allow empty strings (defaults to false)
         * @return {Boolean}
         * @markdown
         */
        isEmpty: function(value, allowEmptyString) {
            return (value =http://www.mamicode.com/== null) || (value === undefined) || (!allowEmptyString ? value === '' : false) || (Ext.isArray(value) && value.length === 0);>
ExtJs--15--Ext.is*各种类型判断的方法,简单看源码就可以明白了