use of strchr() giving error

Question

I am trying to find the occurrence of characters of one string(s1) in other string(s2).

This is part of my code.

for(;i<strlen(s1);i++)
{
   int x=strchr(s2,s1[i]);
   if(x>0)
   count++;
}

But on compiling I get an error pointing to strchr() and says

error: invalid conversion from ‘char*’ to ‘int’ [-fpermissive]

Anyone explain what is problem in using strchr() function.

The problem is that you didn't read its documentation. I'm wondering why would you **ever** try using a function when you **know** you have no idea what it is doing... — , Feb 08 '14 at 06:47

Grijesh Chauhan · Accepted Answer · 2014-02-08T06:47:04.070

2

Assignment is wrong strchr doesn't returns int but returns address of first char in string found:

int x=strchr(s2,s1[i]);

should be:

char* x = strchr(s2, s1[i]); 
//         ^ returns char*

Read manual

char *strchr(const char *s, int c);

RETURN VALUE
The strchr() and strrchr() functions return a pointer to the matched character or NULL if the character is not found. The terminating null byte is considered part of the string, so that if c is specified as '\0', these functions return a pointer to the terminator.

And so:

if(x>0)

should be:

if(x != NULL)

or just if(x)

edited Feb 08 '14 at 06:47

answered Feb 08 '14 at 06:41

Grijesh Chauhan

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how to return position of character in string?? – nomorequestions Feb 08 '14 at 08:21
@user3160274 if you wants to use `strchr()` then you can use pointer difference `ptrdiff_t index = x - s2` Although you should use `ptrdiff_t` – Grijesh Chauhan Feb 08 '14 at 08:27
1

@user3160274 check this working C code @[codepad](http://codepad.org/zwBe3LA5) – Grijesh Chauhan Feb 08 '14 at 08:38
Is there any faster function that can be used to get the position of character in a string? – nomorequestions Feb 08 '14 at 08:42
@user3160274 I don't have any idea but you can write your own: `int indexof(char* str, char c){ int index = 0; while(*str && *str != c) index++; return index;}` – Grijesh Chauhan Feb 08 '14 at 08:45
are you sure its correct?? function doesn't return anything.. you should increment character pointer. – nomorequestions Feb 08 '14 at 08:59
@user3160274 No indexof() I commented is not correct as I forgot to `str++` the codrrect code is @[codepad](http://codepad.org/7b9iMAiB) – Grijesh Chauhan Feb 08 '14 at 09:07

use of strchr() giving error

1 Answers1