Introduction:
I am going to explain you the functionality of for in loop, because for-in loop is a little more different from other loops.
In Java Script there is another loop which is known as For-in Loop. It is used to loop through properties of an object. There are various objects like Navigator objects and Window objects which I will be explaining later on. These objects contain various properties which can be easily accessed using. The example given below gives an idea about what is for-in loop and why it is used.
Syntax of for-in Loop:
for (variable in object)
{
Code to be executed
}
Example:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
</head>
<body>
<script type="text/javascript"><!--
var WinProperty;
document.write("Window Object Properties Names<br /> ");
for (WinProperty in window) {
document.write(WinProperty);
document.write("<br />");
}
document.write("Exiting from the loop!");
--> </script>
</body>
</html>
It list out various properties of Window object. In similar way we can list of other object properties. In each iteration one property of an object is assigned in a variable WinProperty. Till all of the property is not accessed and assigned to the variable the for-in loop will continue executing and printing the property name on the screen.
This loop differs from the for loop, that for loop does not work on objects
Output:
Conclusion:
In this article I explained the concept of for-in loop and how it works, how it differs from for loop.
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