Question

void hello(){
   char a,b;
}

函数const isName = req => { return user .find({ where: { name: req.body.name } }) .then(row => { return row == null ? true : false; }); };没有返回值。这个简单的代码isName()没有返回值，但我确信它正在运行。是什么原因？

Answer 1

查询是异步的，因此请确保等待结果并发送：

// I guess it's a route handler
const isName = async (req, res) => {
    const result = await user
        .find({ where: { name: req.body.name } })
        .then(row => row === null); // same as row === null ? true : false;

     res.send(result);
 };

Answer 2

问题：

isName().then(isThere => { // <------- To get value you should handle like this
    if(isThere) {

    } else {

    }
})

所以你不能像isName（）一样调用并得到预期的结果，诺言应该处理以获得预期的结果

解决方案：

from xlwings import constants
validation_list = "linear_benefit,linear_cost,sigmoid_benefit,sigmoid_cost"
dv_type = constants.DVType.xlValidateList
dv_alertstyle = constants.DVAlertStyle.xlValidAlertStop
dv_operator = constants.FormatConditionOperator.xlEqual
rng.api.Validation.Add(dv_type, dv_alertstyle, dv_operator, validation_list)

函数不返回值

2 个答案: