Difference between revisions of "C-and-C++/C2/Scope-Of-Variables/Gujarati"
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| 00.01 | | 00.01 | ||
− | |C | + | | Welcome to the spoken tutorial on Scope of variables in C and C++. |
|- | |- | ||
| 00.08 | | 00.08 | ||
− | | | + | |In this tutorial we will learn, |
|- | |- | ||
| 00.11 | | 00.11 | ||
− | | | + | | What is the Scope of variable? |
|- | |- | ||
| 00.13 | | 00.13 | ||
− | | | + | | What is a Global variable? |
|- | |- | ||
| 00.16 | | 00.16 | ||
− | | | + | | What is a Local variable? |
|- | |- | ||
| 00.19 | | 00.19 | ||
− | | | + | |Few examples. |
|- | |- | ||
| 00.22 | | 00.22 | ||
− | | | + | |We will also see some common errors and their solutions. |
|- | |- | ||
|00.27 | |00.27 | ||
− | | | + | | To record this tutorial, I am using |
|- | |- | ||
| 00.30 | | 00.30 | ||
− | | | + | |'''Ubuntu Operating System''' version 11.04, '''gcc''' and '''g++''' '''Compiler''' version 4.6.1 |
|- | |- | ||
| 00.41 | | 00.41 | ||
− | | | + | | Let us start with the introduction to the scope of variables. |
|- | |- | ||
| 00.47 | | 00.47 | ||
− | | | + | |It is the region of code within which the variable can be accessed. |
|- | |- | ||
| 00.54 | | 00.54 | ||
− | | | + | |Depending on its type and place of declaration it is divided into two categories: |
|- | |- | ||
| 00.59 | | 00.59 | ||
− | | | + | |Global Variable & |
|- | |- | ||
| 01.02 | | 01.02 | ||
− | | | + | |Local Variable. |
|- | |- | ||
|01.05 | |01.05 | ||
− | | | + | | Now we will see an example, |
|- | |- | ||
| 01.07 | | 01.07 | ||
− | | | + | |I have already typed the program on the editor, |
|- | |- | ||
| 01.10 | | 01.10 | ||
− | | | + | |Let me open it |
|- | |- | ||
| 01.14 | | 01.14 | ||
− | | | + | |Note that our file name is '''scope.c.''' |
|- | |- | ||
| 01.19 | | 01.19 | ||
− | | | + | |Let me explain the code now. |
|- | |- | ||
| 01.23 | | 01.23 | ||
− | | | + | |This is our '''header file.''' |
|- | |- | ||
|01.26 | |01.26 | ||
− | | | + | | Here we have declared two global variables '''a and b.''' |
|- | |- | ||
| 01.32 | | 01.32 | ||
− | | | + | |And we have '''initialized''' them by assigning values as '''5 and 2.''' |
|- | |- | ||
| 01.39 | | 01.39 | ||
− | | | + | |A global variable is available to all functions in your program. |
|- | |- | ||
| 01.44 | | 01.44 | ||
− | | | + | |These are declared outside any functions above main() funtion. |
|- | |- | ||
| 01.51 | | 01.51 | ||
− | | | + | |These have a Global scope.''' |
|- | |- | ||
| 01.53 | | 01.53 | ||
− | | | + | | Here we have declared a '''function''' '''add '''without''' arguments.''' |
|- | |- | ||
|01.59 | |01.59 | ||
− | | | + | | Here sum is a local variable it is declared inside the function add. |
Line 115: | Line 115: | ||
|- | |- | ||
| 02.07 | | 02.07 | ||
− | | | + | |A local variable is available only to the function inside which it is declared. |
|- | |- | ||
| 02.13 | | 02.13 | ||
− | | | + | |These variables are declared inside a block. |
|- | |- | ||
| 02.16 | | 02.16 | ||
− | | | + | |'''These have local scope.''' |
|- | |- | ||
| 02.19 | | 02.19 | ||
− | | | + | |Then sum of a & b will be stored in the variable sum . Here we print the sum |
|- | |- | ||
| 02.29 | | 02.29 | ||
− | | | + | | This is our '''main function.''' |
|- | |- | ||
| 02.33 | | 02.33 | ||
− | |'''add''' | + | | The '''add''' function is called and then executed. |
|- | |- | ||
| 02.38 | | 02.38 | ||
− | | | + | | And This is our return statement. |
|- | |- | ||
|02.40 | |02.40 | ||
− | | | + | | Now Click on save. |
|- | |- | ||
| 02.43 | | 02.43 | ||
− | | | + | | Let us execute the program. |
|- | |- | ||
| 02.45 | | 02.45 | ||
− | | | | + | | | Please open the terminal window by pressing '''Ctrl, ''Alt'' and T''' keys simultaneously on your keyboard. |
|- | |- | ||
| 02.55 | | 02.55 | ||
− | | | + | | To compile type, |
|- | |- | ||
| 02.56 | | 02.56 | ||
− | |'''gcc scope.c -o sco''' | + | |'''gcc scope.c -o sco''' and press enter. |
|- | |- | ||
| 03.05 | | 03.05 | ||
− | | | + | |To execute |
|- | |- | ||
| 03.06 | | 03.06 | ||
− | |'''./sco''' | + | |Type'''./sco''' press enter |
|- | |- | ||
| 03.10 | | 03.10 | ||
− | | | + | | the output is displayed as |
|- | |- | ||
Line 179: | Line 179: | ||
|- | |- | ||
| 03.16 | | 03.16 | ||
− | | | + | | Now let us see how to execute the same program in C++. |
|- | |- | ||
| 03.20 | | 03.20 | ||
− | | | + | | Come back to our program. First press Shift ''Ctrl' & ''S'' key simultaneously on your keyboard |
|- | |- | ||
| 03.31 | | 03.31 | ||
− | | | + | |Now Save the file''' '''with''' an extension .cpp ''' and click on save |
|- | |- | ||
| 03.41 | | 03.41 | ||
− | |'''iostream.''' | + | | Let us change the header file as'''iostream.''' |
|- | |- | ||
| 03.47 | | 03.47 | ||
− | | | + | | Now include the '''using '''statement click on save . |
|- | |- | ||
| 03.58 | | 03.58 | ||
− | | | + | | The declaration of global variable and local variable is same in C++ |
|- | |- | ||
| 04.03 | | 04.03 | ||
− | | | + | |So no need to change anything |
|- | |- | ||
| 04.07 | | 04.07 | ||
− | | | + | | Now replace the '''printf '''statement with the '''cout''' statement |
Line 215: | Line 215: | ||
|- | |- | ||
| 04.13 | | 04.13 | ||
− | | '' | + | | Delete the '''format specifier''' and '\n' |
|- | |- | ||
| 04.17 | | 04.17 | ||
− | | | + | |now delete the comma . |
|- | |- | ||
| 04.19 | | 04.19 | ||
− | | | + | | Type two opening angle brackets |
|- | |- | ||
| 04.22 | | 04.22 | ||
− | | | + | |Delete the closing bracket again type two opening angle bracket |
|- | |- | ||
| 04.26 | | 04.26 | ||
− | | | + | |and within the double quotes type backslash n. Now click on save |
|- | |- | ||
| 04.35 | | 04.35 | ||
− | | | + | |Let us execute the program |
|- | |- | ||
| 04.39 | | 04.39 | ||
− | | | + | |Come back to a terminal. |
|- | |- | ||
| 04.42 | | 04.42 | ||
− | | | + | | To compile type, '''g++ scope.cpp -o sco1, ''' |
|- | |- | ||
| 04.52 | | 04.52 | ||
− | | | + | | Here we have ,'''./sco1''', because We don't want to overight output parameter sco1 file for the scope .c now press enter |
|- | |- | ||
| 05.07 | | 05.07 | ||
− | | | + | | To execute type'''./sco1''' and press enter . the output is displayed as, |
|- | |- | ||
Line 261: | Line 261: | ||
|- | |- | ||
| 05.19 | | 05.19 | ||
− | | | + | | we can see that it is similar to our C code, Now we will see some common errors which we can come across. |
|- | |- | ||
| 05.31 | | 05.31 | ||
− | | | + | |Come back to our program, Suppose here I will declare a variable '''a''' again, |
|- | |- | ||
| 05.41 | | 05.41 | ||
− | |'''int a ; | + | |Type '''int a ;''' |
|- | |- | ||
| 05.45 | | 05.45 | ||
− | | | + | | Click on save. We have declared the variable ''a'' above the main function and after the add function ,let us see what happens. |
|- | |- | ||
| 05.57 | | 05.57 | ||
− | | | + | |Come back to our terminal. |
|- | |- | ||
|06.01 | |06.01 | ||
− | | | + | | Now compile as before , |
|- | |- | ||
|06.05 | |06.05 | ||
− | | | + | |We see errors , Redefinition of ''int''a , ''int'' a previously defined here. come back to our program |
|- | |- | ||
|06.18 | |06.18 | ||
− | |'''a''' | + | |'''a''' is a global variable. |
+ | |||
|- | |- | ||
|06.20 | |06.20 | ||
− | | | + | |It has a '''global scope.''' |
|- | |- | ||
|06.22 | |06.22 | ||
− | | | + | |We cannot declare the variable twice as it is already declared globally |
|- | |- | ||
|06.27 | |06.27 | ||
− | | | + | |We can only declare '''variable a''' as a local variable . |
Line 310: | Line 311: | ||
|- | |- | ||
|06.34 | |06.34 | ||
− | | | + | |Let us fix the error. |
|- | |- | ||
| 06.36 | | 06.36 | ||
− | | | + | | Delete this . |
|- | |- | ||
| 06.39 | | 06.39 | ||
− | | | + | | Click on save. |
|- | |- | ||
| 06.41 | | 06.41 | ||
− | | | + | | Let us execute again. |
|- | |- | ||
|06.42 | |06.42 | ||
− | | | + | |Come back to our terminal. |
|- | |- | ||
| 06.45 | | 06.45 | ||
− | | | + | | Now compile as before, execute as before. |
|- | |- | ||
| 06.49 | | 06.49 | ||
− | | | + | | Yes it is working. |
|- | |- | ||
|06.52 | |06.52 | ||
− | | | + | |This brings us to the end of this tutorial. |
|- | |- | ||
| 06.56 | | 06.56 | ||
− | | | + | | let us summarise |
|- | |- | ||
| 06.58 | | 06.58 | ||
− | | | + | | In this tutorial we learn't , |
− | + | ||
|- | |- | ||
| 07.00 | | 07.00 | ||
− | | | + | | Scope of variable, |
− | + | ||
|- | |- | ||
| 07.02 | | 07.02 | ||
− | | | + | | Global variable, e.g : int a=s & |
− | + | ||
|- | |- | ||
| 07.07 | | 07.07 | ||
− | | | + | | And local variable ,e.g:int sum |
|- | |- | ||
| 07.12 | | 07.12 | ||
− | | | + | | As an assignment, |
|- | |- | ||
|07.14 | |07.14 | ||
− | |Write a program to print the difference of two numbers | + | |Write a program to print the difference of two numbers. |
|- | |- | ||
| 07.19 | | 07.19 | ||
− | | | + | | Watch the video available at the link shown below . |
|- | |- | ||
|07.22 | |07.22 | ||
− | | | + | |It summarises the Spoken Tutorial project. |
|- | |- | ||
|07.25 | |07.25 | ||
− | | | + | |If you do not have good bandwidth, you can download and watch it. |
|- | |- | ||
| 07.30 | | 07.30 | ||
− | | | + | | The Spoken Tutorial Project Team, |
|- | |- | ||
|07.32 | |07.32 | ||
− | | | + | |Conducts workshops using spoken tutorials . |
|- | |- | ||
|07.35 | |07.35 | ||
− | | | + | |Gives certificates to those who pass an online test . |
|- | |- | ||
|07.40 | |07.40 | ||
− | | | + | |For more details, please write to,contact@spoken-tutorial.org |
|- | |- | ||
| 07.47 | | 07.47 | ||
− | | | + | | Spoken Tutorial Project is a part of the Talk to a Teacher project. |
|- | |- | ||
|07.52 | |07.52 | ||
− | | | + | |It is supported by the National Mission on Education through ICT, MHRD, Government of India. |
|- | |- | ||
|08.00 | |08.00 | ||
− | | | + | |More information on this Mission is available at: http://spoken-tutorial.org\NMEICT-Intro. |
|- | |- | ||
| 08.04 | | 08.04 | ||
− | | IIT | + | | This is Ashwini Patil from IIT Bombay signing off |
|- | |- | ||
|08.08 | |08.08 | ||
− | | | + | |Thank You for watching. |
|} | |} |
Revision as of 17:11, 9 July 2013
Time' | Narration |
00.01 | Welcome to the spoken tutorial on Scope of variables in C and C++. |
00.08 | In this tutorial we will learn, |
00.11 | What is the Scope of variable? |
00.13 | What is a Global variable? |
00.16 | What is a Local variable? |
00.19 | Few examples. |
00.22 | We will also see some common errors and their solutions. |
00.27 | To record this tutorial, I am using |
00.30 | Ubuntu Operating System version 11.04, gcc and g++ Compiler version 4.6.1 |
00.41 | Let us start with the introduction to the scope of variables. |
00.47 | It is the region of code within which the variable can be accessed. |
00.54 | Depending on its type and place of declaration it is divided into two categories: |
00.59 | Global Variable & |
01.02 | Local Variable. |
01.05 | Now we will see an example, |
01.07 | I have already typed the program on the editor, |
01.10 | Let me open it |
01.14 | Note that our file name is scope.c. |
01.19 | Let me explain the code now. |
01.23 | This is our header file. |
01.26 | Here we have declared two global variables a and b. |
01.32 | And we have initialized them by assigning values as 5 and 2. |
01.39 | A global variable is available to all functions in your program. |
01.44 | These are declared outside any functions above main() funtion. |
01.51 | These have a Global scope. |
01.53 | Here we have declared a function add without arguments. |
01.59 | Here sum is a local variable it is declared inside the function add.
|
02.07 | A local variable is available only to the function inside which it is declared. |
02.13 | These variables are declared inside a block. |
02.16 | These have local scope. |
02.19 | Then sum of a & b will be stored in the variable sum . Here we print the sum |
02.29 | This is our main function. |
02.33 | The add function is called and then executed. |
02.38 | And This is our return statement. |
02.40 | Now Click on save. |
02.43 | Let us execute the program. |
02.45 | Please open the terminal window by pressing Ctrl, Alt and T keys simultaneously on your keyboard. |
02.55 | To compile type, |
02.56 | gcc scope.c -o sco and press enter. |
03.05 | To execute |
03.06 | Type./sco press enter |
03.10 | the output is displayed as |
03.13 | Sum of a and b is 7 |
03.16 | Now let us see how to execute the same program in C++. |
03.20 | Come back to our program. First press Shift Ctrl' & S key simultaneously on your keyboard |
03.31 | Now Save the file with an extension .cpp and click on save
|
03.41 | Let us change the header file asiostream.
|
03.47 | Now include the using statement click on save . |
03.58 | The declaration of global variable and local variable is same in C++ |
04.03 | So no need to change anything |
04.07 | Now replace the printf statement with the cout statement
|
04.13 | Delete the format specifier and '\n' |
04.17 | now delete the comma . |
04.19 | Type two opening angle brackets |
04.22 | Delete the closing bracket again type two opening angle bracket |
04.26 | and within the double quotes type backslash n. Now click on save |
04.35 | Let us execute the program
|
04.39 | Come back to a terminal. |
04.42 | To compile type, g++ scope.cpp -o sco1,
|
04.52 | Here we have ,./sco1, because We don't want to overight output parameter sco1 file for the scope .c now press enter |
05.07 | To execute type./sco1 and press enter . the output is displayed as, |
05.17 | Sum of a and b is 7. |
05.19 | we can see that it is similar to our C code, Now we will see some common errors which we can come across. |
05.31 | Come back to our program, Suppose here I will declare a variable a again, |
05.41 | Type int a ; |
05.45 | Click on save. We have declared the variable a above the main function and after the add function ,let us see what happens. |
05.57 | Come back to our terminal. |
06.01 | Now compile as before ,
|
06.05 | We see errors , Redefinition of inta , int a previously defined here. come back to our program |
06.18 | a is a global variable.
|
06.20 | It has a global scope.
|
06.22 | We cannot declare the variable twice as it is already declared globally
|
06.27 | We can only declare variable a as a local variable .
|
06.34 | Let us fix the error. |
06.36 | Delete this . |
06.39 | Click on save. |
06.41 | Let us execute again.
|
06.42 | Come back to our terminal. |
06.45 | Now compile as before, execute as before. |
06.49 | Yes it is working.
|
06.52 | This brings us to the end of this tutorial. |
06.56 | let us summarise |
06.58 | In this tutorial we learn't , |
07.00 | Scope of variable, |
07.02 | Global variable, e.g : int a=s & |
07.07 | And local variable ,e.g:int sum |
07.12 | As an assignment,
|
07.14 | Write a program to print the difference of two numbers. |
07.19 | Watch the video available at the link shown below .
|
07.22 | It summarises the Spoken Tutorial project.
|
07.25 | If you do not have good bandwidth, you can download and watch it. |
07.30 | The Spoken Tutorial Project Team,
|
07.32 | Conducts workshops using spoken tutorials .
|
07.35 | Gives certificates to those who pass an online test .
|
07.40 | For more details, please write to,contact@spoken-tutorial.org |
07.47 | Spoken Tutorial Project is a part of the Talk to a Teacher project.
|
07.52 | It is supported by the National Mission on Education through ICT, MHRD, Government of India.
|
08.00 | More information on this Mission is available at: http://spoken-tutorial.org\NMEICT-Intro. |
08.04 | This is Ashwini Patil from IIT Bombay signing off
|
08.08 | Thank You for watching. |