20.TYPE CASTING IN C PART-1(IMPLICIT TYPE CASTING)

C is widely used in education, in application programs like text editors, windows based applications, in games like Quake III, in calculations like finding interest, and for sorting, maintaining and organizing large amounts of data. C programs are used in engineering applications like plotting of curves, integration and many more things. C has been used in very complex things also, e.g. Operating systems like Microsoft Windows, GNU/Linux and other Unices (SunOS, FreeBSD, et al) have also been written partly in C.

C was developed by Denis Ritchie in the 1970s, at the AT&T Bell Laboratories in Murray Hill, New Jersey. Developers of UNIX needed a small and compact language to write their UNIX code. Thus, C was written jointly by Ken Thompson and Dennis Ritchie. The first book on C which gave an informal specification was written by Dennis Ritchie and Brian Kernighan. Brian Kernighan was a computer scientist at AT&T and Bell labs. He is also the author of the famous Hello World program.

C Data Types
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In C, there is a concept called "datatypes". Data types indicate the type of data a variable can hold. When a variable is defined, a memory location will be assigned to the newly defined variable and it will also define the type of data that memory location will hold. C has following data types

int - an integer; reflects size of integers on host machine

float - single-precision floating point

double - double-precision floating point

char - character, a single byte

In addition to basic data types C also defines certain qualifiers to these data types. Qualifiers are used to make variable declaration more specific to variable uses. Qualifiers available in the C language are:

short (applied to integers)

long (applied to integers)

signed (applied to char, or any integer)

unsigned (applied to char, or any integer)