hi, i don't understand why this if condition don't need any "condition" and is always true.
#include <string.h>
#include <stdio.h>
int main() {
char text[] = "I learn C programming because it’s fun";
char *ptr, c = 'u';
ptr = strrchr(text, c);
if (ptr)
{
printf("The position of ’%c’ is: %d\n", c, ptr-text);
}
printf("The character was not found\n");
return 0;
}
why the if condition is always true?
Because 'u'
is in the string.
Try
ptr = strrchr(text, 'q');
and see what happens.
strrchr
returns a pointer to the character searched for or NULL when the character isn't found.
As for:
... why this if condition don't need any "condition"
In C anything that can be converted to an integer value can be used as a condition. Example:
int x = 42;
if (x)
{
// do something
}
Here x
is a condition. It is the same as saying
int x = 42;
if (x != 0)
{
// do something
}
Anything that isn't "zero" are considered TRUE in C.
This goes for pointers as well:
int* p = NULL;
p = whatever...;
if (p)
{
// do something isn't NULL
}
else
{
// p is NULL so do something else
}
which can also be written as:
int* p = NULL;
p = whatever...;
if (p != NULL)
{
// do something isn't NULL
}
else
{
// p is NULL so do something else
}
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