In C, we have 32 keywords, which have their predefined meaning and cannot be used as a variable name. These words are also known as “reserved words”. It is good practice to avoid using these keywords as variable name. These are –
“auto, break, case, char, const, continue, double, default, do, else, enum, exturn, float, for, goto, if, int, long, register, return, short, signed, sizeof, static, struct, switch, typedof, union, unsinged, void, volatile, while”
Basics usage of these keywords –
if, else, switch, case, default – Used for decision control programming structure.
break – Used with any loop OR switch case.
int, float, char, double, long – These are the data types and used during variable declaration.
for, while, do – types of loop structures in C.
void – One of the return type.
goto – Used for redirecting the flow of execution.
auto, signed, const, extern, register, unsigned – defines a variable.
return – This keyword is used for returning a value.
continue – It is generally used with for, while and dowhile loops, when compiler encounters this statement it performs the next iteration of the loop, skipping rest of the statements of current iteration.
enum – Set of constants.
sizeof – It is used to know the size.
struct, typedef – Both of these keywords used in structures (Grouping of data types in a single record).
union – It is a collection of variables, which shares the same memory location and memory storage.