C program to check if a given string is Keyword or not?

C Server Side Programming Programming

Keyword is a predefined or reserved word which is available in C++ library with a fixed meaning and used to perform an internal operation. C++ Language supports more than 64 keywords.

Every Keyword exists in lower case letters like auto, break, case, const, continue, int etc.

32 Keywords in C++ Language which is also available in the C language.

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

These are 30 reserved words that were not in C, but added to C++

asm	dynamic_cast	namespace	reinterpret_cast
bool	explicit	new	static_cast
catch	false	operator	template
class	friend	private	this
const_cast	inline	public	throw
delete	mutable	protected	true
try	typeid	typename	using
using	using	wchar_t

Input: str=”for”
Output: for is a keyword

Explanation

Keywords are reserved words which cannot be used as variable names in program.
There are 32 keywords in the C programming language.

Compare the string with each keyword if the string is same then string is keyword

Example

Live Demo

#include <stdio.h>
#include <string.h>
int main() {
   char keyword[32][10]={
      "auto","double","int","struct","break","else","long",
      "switch","case","enum","register","typedef","char",
      "extern","return","union","const","float","short",
      "unsigned","continue","for","signed","void","default",
      "goto","sizeof","voltile","do","if","static","while"
   } ;
   char str[]="which";
   int flag=0,i;
   for(i = 0; i < 32; i++) {
      if(strcmp(str,keyword[i])==0) {
         flag=1;
      }
   }
   if(flag==1)
      printf("%s is a keyword",str);
   else
      printf("%s is not a keyword",str);
}