C programming language for beginners
- 2. Instructions are very much similar to sentences/statements in English language. It is the combination of various tokens, character set elements to perform a desired task/output to help a program make it complete. OR Instructions in C are the commands in the program that will instruct C compiler to perform specific tasks or actions. Whenever we write a C instruction, we are telling C compiler to do a task for us.
- 3. Following are the categories of instructions: Declaration instructions Input/output instructions Assignment instructions Arithmetic/logical instructions Control instructions
- 4. These are used to declare different kind of variable further to be used by the C program. Eg:- we want to make a program and declare the variable suppose, we want to write the area of rectangle. So the declaration is int A, B, Area; OR int l, b, area; We want to add two numbers, then the declarations is int A, B, sum;
- 5. Input instructions are used for supplying values to the variables as declared in declarative instructions. Eg:- (Statically supplying the values to the variables) A=10; B=20; Where the values of variables are fixed. (for dynamically supplying the value) then we use a C library function called scanf( ) output instructions are used for printing the output after the execution of instructions. Then we use a C library function called printf( );
- 6. These are used for assigning the values in proper order to the variables. int A, B, C; printf(“Enter the first number”); scanf(“%d”,&A); printf(“Enter the second number”); scanf(“%d”,&B); printf(“Enter the third number”); scanf(“%d”,&C);
- 7. These are used for applying the arithmetic formula or logic to solve the problems. Eg:- we need to give a logical instruction to out program area=l * b; OR area = A * B; These are used to control the flow of execution of the program.
- 8. SR.NO . TYPES & DESCRIPTION 1 Basic Types They are arithmetic types and are further classified into: (a) integer types and (b) floating-point types. 2 Enumerated types It is a user defined data type. It gives numbers to the name. 3 The type void The type especifier void indicates that no value is available. 4 Derived types They include (a) Pointer types, (b) Array types, (c) Structure types, (d) Union types (e) Function types.
- 9. TYPE SIZE RANGE FORMAT SPECIFIER Int or signed int 2 -32768 to 32767 %d,%i Unsigned int 2 0 to 65535 %u Short int or signed short int 1 -128 to 127 %hd Unsigned short int 1 0 to 255 %hu Long int or signed long int 4 -2,147,483,648 to 2,147,483,647 %ld Unsigned long int 4 0 to 4,294,967,295 %lu Float 4 3.4E-38 to 3.4E+38 %f Double 8 1.7E-308 to 1.7E+308 %lf Long double 10 3.4E-4932 to 1.1E+4932 %Lf or %LF Char or signed char 1 -128 to 127 %c Unsigned char 1 0 to 255 %c
- 10. #include<stdio.h> #include<conio.h> void main( ) { int A, B, C; clrscr( ); printf(“Enter the first number-”); scanf(“%d”,&A); printf(“Enter the second number-”); scanf(“%d”,&B); C=A+B; printf(“%d”,C); getch( ); } Header section Program execution starts with main( ) function Declaration section Clearing the screen function Assignment section Arithmetic section Printing output statement Take input from keyboard Body section
- 11. stdio.h Standard input output header file This header files contains the definition of standard Input output functions used by a C program. Eg:- printf( ); scanf( ); Output Input
- 12. conio.h Console input ouput header file This header file contains the definition of standard input output functions used by C program related to console input output devices. Eg:- keyboard for input monitor for output The function needed for supplying the input data via keyboard and to get output data via monitor are defined inside <conio.h> library header file. clrscr( ); getch( ); Clear the screen Get character
- 13. void main( ) C compiler starts its compilation from main( ). Before compilation these is another process known as pre-processing takes place. During pre-processing, the header files are to be declared in this section. Some important points to be noted while you make any program C program is case sensitive All the statements are end with semicolon ( ; ) You must have to include header files Space values are ignored in C.