C tokens
Constant
About C-Language and programming:
C Language is well suited for structured programming. It’s requiring the user to think of a problem in terms of function modules or blocks. A proper collection of these function modules would make a complete program.
A C Program is basically a collection of functions that are supported by the C library. User can add own functions to the C library.
Introduction:
C Language is well suited for structured programming. It’s requiring the user to think of a problem in terms of function modules or blocks. A proper collection of these function modules would make a complete program.
A C Program is basically a collection of functions that are supported by the C library. User can add own functions to the C library.
Let us see a simple C-Program:
#include(stdio.h) /*This part called header file */
main() /* main function of C-Program */
{
/* Here is a print function */
printf(“ooh,hoo, Is this C Program”);
} /* End of main function */
The first line informs the system that the function and keywords used in this program are define in inbuilt stdio.h file. The second line informs about the name of the C-Programming and the execution begins at this line. The main() function is the key function of C-Language, that tell to the computer where the programming starts.
The empty pair of parentheses”()” indicates that the function main has no arguments.
*Note: Argument is some value that would be transfer at the time of function call. Details about the argument will be discussed next.
The opening brace “{“indicate the start of function body and closing brace “}”indicate the end of function body. Generally the contents in between to brace are called function body. Function body contains a set of instructions.
In the above example main function body contains a printf() function or statement. This function is used to show the line “ooh,hoo, Is this C Program” on the screen.
So the output of the simple c program is:
ooh,hoo, Is this C Program
*Note: Every statement in C Programming should end with semicolon (;).
C-Tokens:
In a passage of text, individual words and punctuation marks are called tokens. In a C-Programming the smallest individual units are known as C-tokens.
Type C tokens:
1. key words (Example: float, int, char)
2. identifiers (Example: main, amount)
3. Constants ( Example: 10, 15.50, -200)
4. String ( Example: “ABCD”,”XYZ”, “SBIT”,”CCCBBB”)
5. Special Symbols (Example: !, {},[])
6. Operators (Example: -,+,*,/)
The fixed value that do not change during the execution time of a C-Programming is called constant.
Constant are two types:
1. Numeric constant : This type of constant are two types a) Integer constant, b) Real constant.
2. Character constant : This type of constant are two types a) Single character, b) String constant.
Example:
Integer type constant: 10, 20, 30 ,-3990, +3400 etc.
Real Constant : 20.50, -40.67, +49.403, -57.87 etc.
Single character constant : ‘x’, ‘y’, ‘5’,’30’,’z’ etc.
String constant : ‘blog’, ’admission’, ’name’ etc.
There are many spical types of character constant namely “Backslash character constant”
Example:
‘\n’ ------ Used to creat new line.
‘\r’------- Used to return carriage
‘\t’----- used to place horizontal tab
‘\v’------ used to place vertical tab
‘\a’ ---- bell
‘\b’----- blank space
‘\0’----null
‘\’’-----single quote
‘\’’’----- double quote.
See you next day… good day/night.
