Keyword, whitespace in C, and data types of C language

Keywords

Keywords is a predefined or reserved word in the C library with a fixed meaning and used to perform an internal operation. C language support 32 keywords. These reserved words may not be used as a constant or variables or any other identifier names. 

 The following list shows the reserved words in C

auto	double	int	struct
break	else	long	switch
case	enum	register	typedef
char	extern	return	union
const	floa	t short	unsigned
continue	for	singed	void
default	goto	sizeof	volatile
do	if	static	while

Witespace in C

A line containing only whitespace, possibly with a comment, is known as a blank line and a C compiler totally ignores it. Whitespace is the term used in C to describe blanks, tabs, newline characters, and comments. Whitespace separates one part of a statement from another and enables the compiler to identify where one element in a statement, such as an int, ends and the next element begins. Therefore, in the following statement in age; there must be at least one whitespace character (usually space) between int and age for the compiler to be able to di statement distinguish them. On the other hand, in the following statement-

fruit = apples + oranges; //get the total fruit

No whitespace c although you are free to include an apple e some if you wish to increase readability.

Data Types 

Data types in C refer to an extensive system used for declaring variables or functions of different types. The type of a variable determines how much space it occupies in storage and how the bit pattern stored is interpreted.

C data types are used to

• Identify the type of a variable when it declared.
• Identify the type of return value of a function. 
• identify the type of a parameter expected by a function. 

Data types available in C language are

• Built-in Data Types...
• fundamental data types (word, in, hae, double, fat, and pointer)
• Derived data types (array, string, and structure) 
• Programmer - defined Data types (structure, union, and enumeration) 

Fundamental Data Types

void	Used to denote the type with no values.
int	Used to denote an integer type
char	Used to denote a charcter type
float, double	Used to denote a floating point type
int*,float *, char *	Used to denote a pointer type

Derived Data types

array	A finite sequence (or table) of variables of the same data type.
string	An array of character variables.
structure	A collection of related variables of the same and/ or different data types.