 The students in this module, we will look at the objects and we will look at the scope of the objects also. Because the scope will vary depending upon how the declarations are made and what the results you are going to get. So, let's look at the module coverage declaring variables and the types of the variables which we covered the scope of the variables and we will examine the scope of the variables and I will show you and demonstrate this using examples and things would be clear. Let's move ahead. So declaring the variables, variables are declared in JavaScript with the where keyword. The following are all valid variable declarations. These are all valid ones, all valid. Variable names can contain uppercase and lowercase letters as well as numbers but they cannot start with a number. Variables cannot contain spaces or other punctuation with the exception of the underscore character. Okay, underscore. This is dash and this is underscore. This is underscore. Solving the variable names are invalid. These are invalid, invalid, invalid. This is a reserved word. This is number one. Okay, these are invalid and these are the valid ones. Take a look at the preceding example whereas the first three variable names are invalid because characters are used that aren't valid at all. Okay, the last variable name where is invalid because it's a reserved keyword. That creates a problem. You can declare multiple variables on the same line of code as follows. Okay, like this. Multiple on the same line. These can be initiated on the same line also. You can initiate on the same line also, initiating over here, over here, over here also. Variable types, variables in JavaScript are not strongly typed. It is not necessary to declare whether a given variable will hold an integer, a floating point number or a string. You can also change the type of data being held within a variable through simple reassignment. Consider this example. This example over here where the variable first holds an integer, but then through another assignment, it changes to hold a string. So this is an integer over here. Okay, and then it becomes a string. Okay, they are not strongly typed. So let's look at the scope of the variables. A variable scope refers to the locations from which its value can be accessed. Variables are globally scored when they are used outside a function. A globally scope variable can be accessed throughout your JavaScript program. In the context of a web page or a document, as you might think of it, you can access and use a global variable throughout. Variables defined within a function are scoped totally within that function. Okay, within that, this is a global one. This is global, global score variable. And this is a locally scoped variable. A global variable called a new variable and a variable called incoming bits, which is local to the do something function. Local to the do something function over here, okay? Both variables are passed to the respective alert functions within the do something function. When the do something function is called the contents of both variables are sent successfully and displayed on the screen as shown over here. So you see that which is the, this is local. Okay, and of course, this is global. So this is how the declaration was made. Now let's look at some more details over here. And what we look is the example of the variable scope. Examining the variable scope, using whatever editing material you are using. Okay, you edit your file, but let's look at the results. Okay, over here we have one, two, three, and four. We have four alerts over here. But what we see over here is only three alerts, one, two, and three. So where is the fourth one? The fourth one, the problem over here is that the portion and another two are within the scope because it's a section on variable scoping. And you see that this was, this over here was local, okay? And this was local and it was called outside the function itself. So that is why it was not displayed. So that is why this fourth one, this is missing. This is not there. So I think now you can understand the scope of the variable and how they are declared and how they are processed. That's all for this module.