Enumerating an Object's Properties

The for...in loop performs the statement for each property.

 
<!DOCTYPE HTML>
<html>
<head>
<title>Example</title>
</head>
<body>
  <script type="text/javascript">
    var myData = {
      name : "JavaScript",
      weather : "Good",
      printMessages : function() {
        document.writeln("Hello " + this.name + ". ");
        document.writeln(this.name +" is " + this.weather + ".");
      }
    };
    
    myData.printMessages();
    
    for ( var prop in myData) {
      document.writeln("Name: " + prop + " Value: " + myData[prop]);
    }
  </script>
</body>
</html>
  
Click to view the demo
Home 
  JavaScript Book 
    Essential Types  

Object:
  1. The Object Type
  2. Enumerating an Object's Properties
  3. Adding and Deleting Properties and Methods
  4. Add new methods to an object
  5. Delete a property or method from an object
  6. Determine If an Object Has a Property
  7. Performing Equality and Identity Tests on Objects