Advanced-C++/C2/Static-Members/English

Title of script: Static in C++

Author: Ashwini Patil

Keywords: static, Video tutorial.

Visual Cue	Narration
Slide 1	Welcome to the spoken tutorial on static members in C++.
Slide 2	In this tutorial we will learn, Static keyowrd. Static data memeber. Static member functions. We will do this with the help of examples.
Slide 3	To record this tutorial, I am using Ubuntu OS version 11.04 gcc and g++ compiler v. 4.6.1
Slide 4	Let us start with the introduction to static. Static means fixed, which cannot change. The word justifies its meaning. If a variable is defined as static, it means that it is initialized. It will remain in the memory till the end of the program. Static variables are initialized to zero before the first object is created.
Slide 5	Static data memebers Members declared as static are the static data members. The keyword specifies that the member is shared by all instance of the class.
Open stat.cpp	Let us see an example. I have already typed the code on the editor. I will explain it.
Point the cursor stat.cpp	Please note that I have saved the file with the name stat.cpp Let me explain the code now.
Highlight class statex {	This is a class named statex.
Highlight private: int x; public: static int sum;	Here, we have declared x as non-static and sum as static variable.
Highlight static int sum; statex() { sum++; x=sum; }	Function statex is public function. In this we have incremented sum. Then value of sum is stored in x.
Highlight static void stat() { cout << "Result is: " << sum<<"\n"; }	Here we have static function stat. We print the sum.
Highlight void number() { cout << "Number is: " << x<<"\n"; } };	Then we have number function. We print the x here. Then class is closed.
Highlight int statex::sum=0;	To declare the static variable globally we use scope resolution operator. To access a static variable we write as: datatype classname::static var name. Now the storage is allocated to variable sum. It is initialized to 0.
Highlight int main()	This is our main function.
Highlight statex o1;	Here o1 are the object of class statex.
statex::stat();	Static function stat is accessed here. Using the class name and scope resolution operator.
statex o2,o3;	We have o2, o3 and o4 objects of class statex.
o2.number(); o3.number();	Now we call the number function using object o1, o2, o3 and o4.
Highlight return 0;	This is the return statement.
Click on save	Now Click on Save.
	Let us execute.
Open the terminal Ctrl, Alt and T keys simultaneously	Please open the terminal by pressing Ctrl, Alt and T keys simultaneously
Type g++ stat.cpp -o st To execute Type ./st	To compile the program type g++ stat.cpp -o st To execute Type ./st
Highlight Output	Here we see, Result is: 1 Number is: 2 Number is: 3
Highlight Output	Let me explain the output now: First the value of sum is 1. Then sum is incemented now the value is 2. Like this it is incremented till 3.
On the editor	Let us go back to our program. Now i will create one more object of class statex as o5.
Type statex o5;	Type statex o5; Now click on save and let us execute and see.
On the terminal	Come back to the terminal. Compile and execute as before.
Highlighted Output	Result is: 2 Number is: 3 Number is: 4
Switch back to the slides	This brings us to the end of this tutorial. Let us come back to the slides.
Slide 7 Summary	In this tutorial, we have seen, static keyword. Static data member. Static function.
Slide 6 Assignment	As an assignment Create a class that declares a static variable. Decrement the variable. And print the value.
Slide 8 About the Spoken Tutorial Project	Watch the video available at the link shown It summarizes the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it
Slide 9 Spoken Tutorial Workshops	The Spoken Tutorial Project Team Conducts workshops using spoken tutorials Gives certificates to those who pass an online test For more details, please write to, contact@spoken-tutorial.org
Slide Number 10 Acknowledgement	Spoken Tutorial Project is a part of the Talk to a Teacher project It is supported by the National Mission on Education through ICT, MHRD, Government of Indiaabout:startpage More information on this Mission is available at: http://spoken-tutorial.org\NMEICT-Intro
	This is Ashwini Patil from IIT Bombay signing off Thank You for joining.

Contributors and Content Editors

Ashwini