INTRODUCTON TO ‘C’ PROGRAM
'C' LANGUAGE INTRODUCTON
- C is a procedural programming language. It was initially developed by Dennis Ritchie between 1969 and 1973.
- It was mainly developed as a system programming language to write operating system.
- The main features of C language include low-level access to memory, simple set of keywords, and clean style, these features make C language suitable for system programming like operating system or compiler development.
- Many later languages have borrowed syntax/features directly or indirectly from C language. Like syntax of Java, PHP, JavaScript and many other languages is mainly based on C language. C++ is nearly a superset of C language (There are few programs that may compile in C, but not in C++).
Beginning with 'C' programming:
Writing first program:
#include <stdio.h> int main(void) { printf(“CREATIVE STELLARS”); return 0; } OUTPUT : CREATIVE STELLARS |
LET US ANALYSE THE PROGRAM LINE BY LINE
Line 1: [ #include <stdio.h> ]
- In a C program, all lines that start with # are processed by preprocessor which is a program invoked by the compiler.
- In a very basic term, preprocessor takes a C program and produces another C program.
- The produced program has no lines starting with #, all such lines are processed by the preprocessor.
- In the above example, preprocessor copies the preprocessed code of stdio.h to our file.
- The ” .h ” files are called header files in C.
These header files generally contain declaration of functions. We need stdio.h for the function printf() used in the program.
Line 2 :[ int main(void) ]
- There must to be starting point from where execution of compiled C program begins.
- In C, the execution typically begins with first line of main().
- The void written in brackets indicates that the main doesn’t take any parameter .
- main() can be written to take parameters also.
- We will be covering that in future posts.
- The int written before main indicates return type of main().
- The value returned by main indicates status of program termination.
Line 3 and 6: [ { and } ]
- In C language, a pair of curly brackets define a scope and mainly used in functions and control statements like if, else, loops.
All functions must start and end with curly brackets.
Line 4 [ printf(“CREATIVE STELLARS”); ]
- printf() is a standard library function to print something on standard output.
The semicolon at the end of printf indicates line termination. In C, semicolon is always used to indicate end of statement.