如何在 JavaScript 中獲取物件的屬性值?


有一些方法可以查詢物件的屬性值,例如 `Object.values()`,但是使用此方法過程會很冗長。

我們可以藉助 `_.values()` 函式輕鬆查詢物件的屬性值,這是一個內建方法,屬於 underscore.js(一個提供多種功能的 JavaScript 庫)。

`_.values()` 方法無需迴圈即可獲取值,它是查詢物件屬性值的直接方法。

語法

_.values( object )

引數 - 此函式只接受一個引數,即物件。物件類似於陣列,具有鍵值對,但它不是陣列。

示例 1

以下是一個從物件中檢索值的示例:

<!DOCTYPE html>
<html>
<body>
   <script src="//cdnjs.cloudflare.com/ajax/libs/lodash.js/0.10.0/lodash.min.js"></script>
</head>
<body>
   <script>
      var obj = {"name": 'Abcd kumar',age: 47, contact:9893444666, "Organization":'Spacex' }
      var res = JSON.stringify(_.values(obj)); // we are using stringify because we want to print the value in page not in console.
      document.write((res));
   </script>
</body>
</html>

示例 2

在這個例子中,我們使用 `object.values()` 函式列印物件的屬性值。

<!DOCTYPE html>
<html>
<body>
   <script src="//cdnjs.cloudflare.com/ajax/libs/lodash.js/0.10.0/lodash.min.js"></script>
</head>
<body>
   <script>
      var userDetails = {name: 'Aman Kumar',state:"Jharkhnad", work:'Technical Writer', company:"TutorialsPoint" };
      for(let value of Object.values(userDetails)){
         document.write(" " + value + " ");
      }
   </script>
</body>
</html>

示例 3

讓我們來看另一個例子:

<!DOCTYPE html>
<html>
<head>
   <script type="text/javascript"src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js"></script>
</head>
<body>
   <script type="text/javascript">
      var details = _.values({
         Name: "Vivek",
         Address: "Noida Up",
         Mobile: "+91 9876452301",
         Email: "tutorialspoint@gmail.com",
      });
      
      //console.log(key);
      for(let value of details){
         document.write(" " + value + " ");
      }
   </script>
</body>
</html>

示例 4

這是一個示例,我們將物件的屬性值以陣列格式打印出來:

<!DOCTYPE html>
<html>
<head>
   <script type="text/javascript"src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js"
></script>
</head>
<body>
   <script type="text/javascript">
      var details = _.values({
         Name: "Vivek",
         Address: "Noida",
         Mobile: "+91 9876452301",
         Email: "tutorialspoint@gmail.com",
      });
      
      var object = _.values({
         name: "Aman Kumar",
         Address: "Hyderabad",
         Mobile: "+91 8252240532",
      });
      
      //console.log(key);
      document.write("[");
      for (let value of details) {
            document.write(" " + value + " ");
         } // here we are using for loop and documet.write() to display the value in page.
         document.write("]");
         
         document.write("[");
         for (let x of object[2]) {
            document.write(x); // get the third item from the list returned as well
         }
         document.write("]");
   </script>
</body>
</html>

更新於:2022-12-06

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