I'm trying to check if a pointer is pointing at some char, like this:
#include<stdio.h>
#include<string.h>
#define a 3
int func(char *);
int main()
{
char *s="a";
int type;
type=func(s);
printf("%d",type);
return 0;
}
int func(char *s)
{
int type;
if(*s=="a")
{
type=1;
}
return type;
}
But I constantly get a warning:
warning: comparison between pointer and integer if(*s=="a")
Is it possible to compare pointers and integers?
Is there another way to resolve this problem?
Can I find out at which letter is pointing *s
without printing it?
"a"
is not a character, it is a string literal. 'a'
is a character literal, which is what you are looking for here.
Also note that in your comparison *s == "a"
it is actually the "a"
which is the pointer, and *s
which is the integer... The *
dereferences s
, which results in the char
(an integer) stored at the address pointed to by s
. The string literal, however, acts as a pointer to the first character of the string "a"
.
Furthermore, if you fix the comparison by changing it to *s == 'a'
, you are only checking whether the first character of s
is 'a'
. If you wish to compare strings, see strcmp
.