如何处理 catch 函数？

Question

我在cloud firestor中创建了一个数据库，所以现在我想通过输入字段向其中添加一些信息，当输入字段为空信息时存储问题并且catch函数不起作用，我该如何修复它，并进行catch功能工作。

这是代码：

HTML：

<div class="container"> 

          <input  type="text" placeholder="Enter the country" id="country-field"  required>

          <p class="selectPar">Enter City</p>

          <input type="text" placeholder="Enter the city" id="city-field" required>

          <p class="selectPar">Enter the place name</p>

          <input type="text" placeholder="Enter the place name" id="placename-field" required>

          <p class="selectPar">Enter Address</p>

          <input type="text" placeholder="Enter the address" id="address-field" required>

          </div>

        </div>

        <div id="btnFrmAlignSec">

          <button id="btnFrm" type="button" onclick="AddToDataBase()">Send to admin</button>

        </div>

JavaScript

函数添加到数据库（）{

  var inputCountry = document.getElementById("country-field").value;

  var inputCity = document.getElementById("city-field").value;

  var inputAddress = document.getElementById("address-field").value;

  var inputNameofPlace = document.getElementById("placename-field").value;

  // Add a new document in collection "cities"

   db.collection("UsersShare").doc().set({

    name:inputNameofPlace,

    city:inputCity,

    country:inputCountry,

    address:inputAddress,

  })

  .then(function() {

    console.log("Document successfully written!");

    document.getElementById("reply").style.display="inline";  

  })

  .catch(function(error) {

    console.error("Error writing document: ", error);

  });

}

Answer 1

if(inputCountry.trim() && inputCity.trim() && inputAddress.trim() &&&nbsp;&nbsp; &nbsp;inputNameOfPlace.trim()){&nbsp; // Add a new document in collection&nbsp;&nbsp; // your code} else {&nbsp;// fields are empty --- error message}

Answer 2

您可以事先检查字段是否为空，如果不是，则对数据库进行操作，否则将错误记录到控制台，就像您的 catch 函数一样：if(inputCountry && inputCity && inputAddress && inputNameOfPlace){&nbsp; &nbsp; db.coll.....} else {&nbsp; &nbsp; console.error('Field(s) are empty');}