1. C Programming

2. A S D F K L ;

3. Computer system
Monitor
CPU
Key Board
mouse

4. Parts of a computer
Processor, memory, hard disk, input, output.
In memory both the program lines and variables are kept
Action is taking place in processor and results are stored there in the memory.
Even the output is given in the output window and flipped back to the edit window

5. Computer system
Monitor
CPU
Key Board
mouse

6. Computer system
memory
Monitor
Hard disk
processor
CPU
Key Board
mouse

7. Steps in executing a code
Write the code (source code)
Compile the source code
If errors go back to edit and correct and repeat compiling
If no errors, the compiler has generated the machine (object code)
Run the (object) code and so get the results

8. void main() { int a = 4,b =7 , c; c = a + b; printf(“ sum is %d” ,c);} 4 a 7 b
junk c

9. void main() { int a = 4,b =7 , c; c = a + b; printf(“ sum is %d” ,c);} 4 a 7 b 11 c

10. void main() { int a = 4,b =7 , c; c = a + b; printf(“ sum is %d” ,c);} 4 a 7 b 11 c
Sum is

11. void main() { int a = 4,b =7 , c; c = a + b; printf(“ sum is %d” ,c);} 4 a 7 b 11 c
Sum is 11

12. printf(“ %d + %d is %d “,a,b,c); }
void main() {
int a = 4,b = 7, c;
c = a + b;
printf(“ %d + %d is %d “,a,b,c); } 4 47 a 7 11 b 11
junk c
4 + 7 = 11

13. What is programming?
Making the computer work as we want it to work
Getting things done by the computer
We write the program in the memory and make the processor work it out

14. What is programming?
Programming is making the computer work as we want it to. ie. we will have to talk to a machine. Some syntax is there. Only a few syntaxes to be byehearted.
A series of instructions to the processor, so that it can do the entire work, without any difficulty. Instructions in a tape recorder or MP3 player to make milk tea!

15. How do we make it work?
We keep a program in memory and ask the processor to execute line by line
It is like a boy following the instructions given to it, systematically and quickly, but without any common sense or mind reading capability. Fast unlike us, obedient unlike us and having no common sense like us?!

16. Vehicle v/s program
If a new vehicle,
draw,
expert opinion,
(----- )finally build and run.
But this expert (compiler) will build it!
So if there is a modification, show to expert/(compile) and only then run

17. The compiler is like an expert
Compiler is the expert who/which tells whether the syntax is correct! If not, we are to correct and again submit. Finally build and test run. Compiler will compile too!
Compiler is also without common sense at times. Logical errors!
Compiler will not correct logical errors. So to know what is happening, print the results, in between or check the values of variables.

18. In Input and output mechanism
If we are to see the result, project them onto the screen (printf)
%d is a place holder in that order
But the result screen will flip back to edit and so get it back by alt f5
order to get values from the key board, scanf

19. Variables and memory address
All the variables to be used must be declared (and so given locations). The dissection of a frog!
The memory address is the uniquely identifying method.
In a college,
register number,
in a town,
the address,

20. The operations possible
Different operators, + - * / but % is also there!
Integer on integer will give only an integer.

21. Some suggestions
Meaningful variable names and function names
Do proper indentation
Results printed should be made meaningful
Do hand tracing
Draw flow charts!
Feel free to ask doubts, loud clear and smart
Free to ask. Loud and smart
Please learn blind typing at the earliest
Note that there are two types of slashes in KB
Use the home and end keys wherever required
Make your own changes and see whether the expected results are obtained

22. Neither copy nor mug up
Do a hand tracing of the programs for understanding on the one side and to find out the mistakes on the other side
Spend some time to plan the program using algorithm or flow chart
Be sure that it is logic and no magic.
Avoid printing results inside the loops
Hard code first and then go for soft coding
Get the addresses from the computer and draw a memory map

23. There are different slashes, \n, \t.... // /* and */
The operations possible
Different operators, + - * / but % is also there!
Integer on integer will give only an integer.
The operator precedence issues.
5+2 * 3 = 11 v/s (5+2) * 3 = 21
Right to left and left to right 2/4*3 v/s 2*3/4
X+1 % 5 v/s (x+1) % 5;

24. See Programming in C
#include<stdio.h>// header file inclusion
void main() {
printf(“Let Us C”); }

25. See Programming in C
#include<stdio.h>
void main()//a must for any C program to work {
printf(“Let Us C”); }

26. See Programming in C
#include<stdio.h>
void main()//see the function braces {
printf(“Let Us C”); }

27. See Programming in C
#include<stdio.h>
void main()//see the function braces
// there is a space between void and main
// main can not be capital! ie. C is case sensitive {
printf(“Let Us C”); }

28. See Programming in C
#include<stdio.h>
void main()//function header {
printf(“Let Us C”); }

29. #include<stdio.h> void main()//function header {
See Programming in C
#include<stdio.h>
void main()//function header {
printf(“Let Us C”); }
If there is a head, there shall be a body after/below the head

30. #include<stdio.h> void main()//function header {// body begins
See Programming in C
#include<stdio.h>
void main()//function header
{// body begins
printf(“Let Us C”);
}// body ends
If there is a head, there shall be a body after/below the head

31. See Programming in C
#include<stdio.h>
void main()//function header {
printf(“Let Us C”);// end of an instruction }

33. End of an instruction is signaled by ;
Every program should have this function and only one main function. No capital M please
DISSECTION of a basic C program
Function braces, simple braces, ellipse. This is to hold or receive parameters or arguments. Presently it is holding nothing
Function body begins
main() {
printf(“Welcome to see the sea of C”); }
Function body ends
printf function takes/holds necessarily one argument which is a string. Starting and ending by ” ”
End of an instruction is signaled by ;
Only one instruction or statement

34. ; #include<stdio.h> printf should have a prototype ? main() {
printf(“\n \tWelcome to see the sea of C”) } ; }
We can add escape sequences and format specifiers in
the string
Statement missing
Compound Statement missing

35. Welcome to see the sea of C
See that C is Ecstatic
#include<stdio.h>
main() {
printf(“\n \tWelcome to see the sea of C”);
printf(“\n See that C is Ecstatic” ); }
Un-terminated string or character constant

36. See Programming in C
#include<stdio.h>
void main() {
printf(“Let Us C”); }

37. Let Us C See Programming in C #include<stdio.h> void main() {
printf(“Let Us C”); }

38. See Programming in C
#include<stdio.h>
void main() {
printf(“Let Us \nC”); }

39. Let Us C See Programming in C #include<stdio.h> void main() {
printf(“Let Us \nC”); }

40. See Programming in C
#include<stdio.h>
void main() {
printf(“Le\tt Us C”); }

41. Le t Us C See Programming in C #include<stdio.h> void main() {
printf(“Le\tt Us C”); }

42. See Programming in C
#include<stdio.h>
void main() {
printf(“Let Us C\bK”); }

43. Let Us K See Programming in C #include<stdio.h> void main() {
printf(“Let Us C\bK”); }

44. See Programming in C
#include<stdio.h>
void main() {
printf(“Let Us C\rG”); }

45. Get Us C See Programming in C #include<stdio.h> void main() {
printf(“Let Us C\rG”); }

46. See Programming in C
#include<stdio.h>
void main() {
printf(“Let Us C\a”); }

47. Let Us C See Programming in C #include<stdio.h> void main() {
printf(“Let Us C\a”); }

48. See Programming in C: Use of Variables
#include<stdio.h>
void main() {
a = 5;
printf(“a = a”); }

49. See Programming in C: Use of Variables
#include<stdio.h>
void main() {
a = 5;
printf(“a = a”); }
Undefined symbol ‘a’ in main

50. See Programming in C: Use of Variables
#include<stdio.h>
void main() {
int a;
printf(“a = a”); }
//integer: used for counting
Whatever you use should be brought in beforehand! The dissection of a frog, or brisk physics practical and instruments are damaged!

51. a = a See Programming in C: Use of Variables #include<stdio.h>
void main() {
int a;
printf(“a = a”); }

52. The value of a is 6785
Data type followed by variable name
Declaration of a variable
#include<stdio.h>
main() {
int a;
printf(“\n The value of a is %d “,a); }
format specifier or place holder and its corresponding expression
Undefined symbol a
Undeclared first use ‘a’

53. See Programming in C: Use of Variables
#include<stdio.h>
void main() {
int a;
a = 5; // initialisatioin
printf(“a = %d”,a); }
//variable declaration

54. a = 5 See Programming in C: Use of Variables #include<stdio.h>
void main() {
int a;
a = 5;
printf(“a = %d”, a); }

55. The value of a is 6
#include<stdio.h>
Declaration & Initialization of a variable
main() {
int a = 6;
printf(“\n The value of a is %d “,a); }

56. 5 + 3 = 8 See Programming in C: Use of Variables
#include<stdio.h>
void main() {
int a=5,b=3,c;
c = a + b;
printf(“%d + %d = %d”,a,b,c); }

57. 5 + 3 = 8 See Programming in C: Use of Variables
#include<stdio.h>
void main() {
int a=5,b=3,c;
c = a + b;
printf(“%d + %d = %d”,a,b,c); }
Place holders in printf statement and the variables listed after the string sit in the place holders in the same order

58. The product 6 * 5 = 30
#include<stdio.h>
main() {
int a,b;
a = 6;
b= 5;
printf(“\n The product %d * %d = %d “,a, b , a*b); }
format specifier or place holder

59. The prod of 6 and 5 is 30
#include<stdio.h>
main() {
int a=6,b=5;
printf(“\n The prod of %d and %d is %d = %d”, a, b , a*b); }
Variable declaration and initialization can be done together for multiple vars

60. The prod of 6 and 5 is 30
#include<stdio.h>
main() {
int a=6,b=5;
printf(“\n The prod of %d and %d is %d = %d”, a, b , a*b); }
Variable declaration and initialization can be done together for multiple vars
But what is the big deal if we know the values in advance? Hard coded values! Why not soft code? Accept from KB during the run time?

61. See Programming in C: accepting of Variables
#include<stdio.h>
void main() {
int a,b;
printf(“enter value of a”);
scanf(“%d”,&a);
b = 2 * a;
printf(“%d x 2 = %d”,a,b); }

62. See Programming in C: accepting of Variables
#include<stdio.h>
void main() {
int a,b;
printf(“enter value of a”);
scanf(“%d”,&a);
b = 2 * a;
printf(“%d x 2 = %d”,a,b); }
627 a
7218 b
In memory

63. See Programming in C: accepting of Variables
Enter value of a
#include<stdio.h>
void main() {
int a,b;
printf(“Enter value of a”);
scanf(“%d”,&a);
b = 2 * a;
printf(“%d x 2 = %d”,a,b); }
627 a
7218 b
In memory

64. See Programming in C: accepting of Variables Enter value of a4
#include<stdio.h>
void main() {
int a,b;
printf(“enter value of a”);
scanf(“%d”,&a);
b = 2 * a;
printf(“%d x 2 = %d”,a,b); } 4 a
7218 b 4
In memory

65. See Programming in C: accepting of Variables
Enter value of a4
#include<stdio.h>
void main() {
int a,b;
printf(“enter value of a”);
scanf(“%d”,&a);
b = 2 * a;
printf(“%d x 2 = %d”,a,b); } 4 a 8 b 4
In memory

66. See Programming in C: accepting of Variables
Enter value of a4
4 x 2 = 8
#include<stdio.h>
void main() {
int a,b;
printf(“enter value of a”);
scanf(“%d”,&a);
b = 2 * a;
printf(“%d x 2 = %d”,a,b); } 4 a 8 b 4
In memory

67. What is this operation? void main() { int a=462,b=10,c,d,e; c = a/b;
d = c * b;
e = a – d;
printf(“ e = %d”,e); } a
b 10
c 856 d
e 0

68. What is this operation? void main() { int a=462,b=10,c,d,e; c = a/b;
d = c * b;
e = a – d;
printf(“ e = %d”,e); } a
b 10
c 46 d
e 0

69. What is this operation? void main() { int a=462,b=10,c,d,e; c = a/b;
d = c * b;
e = a – d;
printf(“ e = %d”,e); } a
b 10
c 46
d 460
e 0

70. What is this operation? void main() { int a=462,b=10,c,d,e; c = a/b;
d = c * b;
e = a – d;
printf(“ e = %d”,e); } a
b 10
c 46
d 460
e 2

71. What is this operation? void main() { int a=462,b=10,c,d,e; c = a/b;
d = c * b;
e = a – d;
printf(“ e = %d”,e); } a
b 10
c 46
d 460
e 2

72. What is this operation? void main() { did a mod operation:
int a=462,b=10,c,d,e;
c = a/b;
d = c * b;
e = a – d;
printf(“ e = %d”,e); }
did a mod operation:
a % 10 operation or the last digit of a a
b 10
c 46
d 460
e 2

73. What is this operation? void main() { int a=462,b=10,c,d,e; c = a/b;
So what is
659 % 10
13 % 10
7 % 10
7 % 4
8 % 4
5 % 4
4 % 4
3 % 4
1 % 4
What is this operation?
void main() {
int a=462,b=10,c,d,e;
c = a/b;
d = c * b;
e = a – d;
printf(“ e = %d”,e); } a
b 10
c 46
d 460
e 2
did an a % 10 operation or the last digit of a

74. #include<stdio.h>
The square of 6 is 36
main() {
int a;
printf(“Enter a num ”);
scanf(“%d”,&a);
printf(“\n The square of %d is %d “,a, a*a); }
We want the values on the run, during execution, ie from the keyboard !
Lest one be blinking, better give a printf statement before scanf.

75. #include<stdio.h>
The square of 6 is 36
main() {
int a;
printf(“Enter a num ”);
scanf(“%d”,&a);
printf(“\n The square of %d is %d “,a, a*a); }
We want the values on the run, during execution, ie from the keyboard !
Lest one be blinking, better give a printf statement before scanf.

76. #include<stdio.h>
The square of 6 is 36
main() {
int a;
printf(“Enter the value of to find square ”);
scanf(“%d”,&a);
printf(“\n The square of %d is %d “,a, a*a); }
We want the values on the run, during execution, ie from the keyboard !
Lest one be blinking, better give a printf statement before scanf.

77. In the memory
Enter the value of a to find square 6
The square of 6 is 36 1
5681 a 6 36
9625 sq
#include<stdio.h> 2
main() {
int a,sq;
printf(“\n Enter the value of a to find square ”);
scanf(“%d”,&a);
sq= a * a;
printf(“\n The square of %d is %d “,a, sq); } 6

78. Common error messages
Statement missing check the semicolon in the previous line
Compound statement missing check whether the closing curly brace is missing
Declaration not allowed check whether the opening curly brace is missing
Un-terminated string or character constant check whether the string which is started is ended or not: any closing double quote missing
Undefined symbol ‘x’ check whether the variable is declared or not
Undefined symbol ‘xyz’,’pqr’,’apwzyd’… Check whether a string starting is missing or not

79. L value expected check whether some constant is being modified
Connot covert int * to int check whether an integer pointer value is being assigned to an integer variable
Too few parameters in the function call check the shortage of parameters in the calling of a function, whereas the function definition or prototype has more parameters
Too many parameters in the function call check the additional parameters in the calling of a function, whereas the function definition or prototype has lesser parameters

80. The sum is void main() { int num = 47,sum = 0, ld; while (num > 0)
ld = num % 10;
sum = sum + ld;
num = num / 10; }
printf(“The sum is “+sum); 4 47
num 7 11 11
sum
junk 4 7 ld

81. 22 23 24 20 21
576
396 63 41 86 20 I j
Void main(){
int I, j, sum= 0;
for(i=20;i<= 23;i++){
sum = sum + i;
printf(“\n the sum is %d and i is %d “,sum,i); }
sum
The sum is 20 and I is 20
The sum is 41 and I is 21
The sum is 63 and I is 22
The sum is 86 and I is 23

82. In the memory
The square of 6 is 36
Enter the value of a to find square 25 9 6 1 81
625
5681 a
9625
#include<stdio.h> 2 81
625 36 sq
main() {
int a,sq,count;
for(count=1,count<=3;count++)
printf(“\n Enter the value to square ”);
scanf(“%d”,&a);
sq= a * a;
printf(“\n The square of %d is %d “,a, sq); } 3
5681 4 3 1 2
count 9 6 25

83. In the memory
The square of 6 is 36
Enter the value of a to find square 9 6 1 81
25 is
625
5681 a
#include<stdio.h>
main() {
int a,sq,count;
for(count=1,icount<=3;count++)
printf(“\n Enter the value to square ”);
scanf(“%d”,&a);
sq= a * a;
printf(“\n The square of %d is %d “,a, sq); }
9625 2
625 36 81 sq 3
5681 3 2 1 4
count 9 6 25

84. Problems to be done
Swapping of two variables
Swapping/rotation among n variables
If statement syntax. Only one side
check pass/even
absolute value
If else statement syntax. both sides
pass or fail/odd or even
biggest among two vars
sort 2 variables
senior/junior
last digit is odd/even
last but one digit odd/even
divisible by 7 or not
Nested if else
3 var biggest
3 var sort
grade s, a, b,c…
incentive upto and then on…
special pass criterion
roots of a quadratic equation
sides of a triangle

85. For loop
With serial numbers
The dynamics of for loop
Printing all the numbers from 1 to 50
Summing up all numbers from 1 to 50
Accepting variables n times and processing them
21 matchstick game
Printing a single star
Printing a line of stars
Printing the digits of a number
Summing up the digits of a number
Convert a number to binary
Check whether a number is palindrome

86. Check whether a number is sliding down or climbing up
Check whether a given number is prime or not
Check whether a number is Armstrong
Perfect number
Single digit sum number or not
Cup number
Grove number
Platau number
Mountain number
Interchangeability of loops
a statement 10 times

87. Nested loops
Printing patterns
Dynamic screen or dance on the screen
Generation of numbers
Prime, Armstrong, perfect, ninean, eighteen...
Cup, mountain, palindrome
Slide numbers, climb up numbers
Oddeven sum equal
Alter sum equal
Triple sum equal
Generation of deadly sevens. Either divisible by 7 or at least one digit is 7

88. Arrays
Declare
Initialize
Print all
Sum all
Modify all
Select on basis
Print function
Sort
Bubble
Selection
Insertion

89. Palarray
Print in reverse order
Reverse array and print
Find out the sum of digits in the array
Arrays and addresses
Pointer concept. Using a pointer, access another var, change it, accept to it
Pointer arithmetic
Double pointer issues. Proper pictorial representations
Printing an array, given any address of the nth element in array

90. Functions
Using built in functions with no arguments clrscr();
Using built in functions with arguments. Printf(“ ab”);
Using built in functions with varying arguments printf(“%d %d “,a,b)
User defined functions, without arguments
User defined functions with arguments
User defined functions return vals
User defined functions with pass by reference arguments

91. Two d arrays
Declaration and initialisation
Printing td arrays
Function to print/use td arrays
16 puzzle
Addresses in two D arrays
Sending any row’s address to a function
Diagonal elements
Major/ minor
Upper major/upper minor

92. Transpose
Addition
multiplication
Border elements
Inner elements
Steering rotation
Inner steering rotation
Check symmetric
Creation of magic square
Sum of rows/cols in a wrapper row/col
Check quadian matrix if every subsquare matrix sum are equal

93. 1 9 11 3 8 16 14 6 5 13 15 7 4 12 10 2

94. Reflections of td arrays
Rotations of td arrays
The cofactor of a matrix
Storage classes in C

95. Strings
Definition
Declaration
Initilisatioin
Searching
Sorting
Two arrays and strings
Malloc and pointer array of storing strings

96. Operations
Substring
Length
No. of vowels
No of words
Concatenation
Palindrome
Reversing a string
Change case of string
Upper/lower/toggle
Sorting of strings

97. Structure
Declaration
Initialisation
Copying
Printing values
Accepting values
By variable
By pointer
Array of structure
Array in a structure
Structure within a structure

98. Unions
Memory allocation
Pre-processor directives