函数return

 findCategory(id) {
// this.Category=[{id:1,name:'ljj'},{id:2,name:'wmy'}]
                    var ar = this.Category.find(function (elem) {
                        return elem.id == id;
                    });
                    return ar.name
                },

 法2

 findCategory(id) {
                    var value
                    this.Category.forEach(item => {
                        if (item.id == id) {
                            value = item.name
                        }     
                    })
                    return value
                },

^(*￣(oo)￣)^：foreach不可以内部直接return

异步函数，async/await,promise目前return出的都是[promise object]