How to compare two char arrays in C? - c

Question

I'm coming from Python and there you can easily compare two strings (char arrays) like that:
if "foo" == "bar":
# ...
How would I do this in C? I already saw this post but it didn't work.
Code:
int main(void) {
char string[100];
printf("Please enter something: ");
fgets(string, 100, stdin);
if (strcmp(string, "a") == 0)
printf("a");
else if (strcmp(string, "b") == 0)
printf("b");
else if (strcmp(string, "c") == 0)
printf("c");
else
printf("something else");
return (0);
}
It prints "something else" though I entered a.

Answer 1

The function fgets can append to the entered string the new line character '\n' that you should remove. For example
fgets(string, 100, stdin);
string[ strcspn( string, "\n" ) ] = '\0';
or
fgets(string, 100, stdin);
char *p = strchr( string, '\n' );
if ( p != NULL ) *p = '\0';
From the C Standard (7.21.7.2 The fgets function)
2 The fgets function reads at most one less than the number of
characters specified by n from the stream pointed to by stream into
the array pointed to by s. No additional characters are read after a
new-line character (which is retained) or after end-of-file. A null
character is written immediately after the last character read into
the array.

Answer 2

The fgets() also takes in the newline character when the user presses the Enter key. So in order to remove that from what is stored in `string[100], just change :
fgets(string, 100, stdin);
to
strtok(fgets(string, 100, stdin), "\n");
to remove the newline character. Just make sure to include the #include <string.h> header
Further Reading
If you are wondering what strtok does, have a look at https://www.tutorialspoint.com/c_standard_library/c_function_strtok.htm
The C library function char *strtok(char *str, const char *delim)
breaks string str into a series of tokens using the delimiter delim.
char *strtok(char *str, const char *delim)

Answer 3

You could answer this question yourself if you did put some research effort.
int main(void) {
char string[100];
printf("Please enter something: ");
fgets(string, 100, stdin);
if (strcmp(string, "a") == 0)
printf("a");
else if (strcmp(string, "b") == 0)
printf("b");
else if (strcmp(string, "c") == 0)
printf("c");
else
{
printf("something else - lets check why:\n Entered string:\n");
for(size_t n = 0; n <= strlen(string); n++)
{
printf("string[%2zu] = ", n);
switch(string[n])
{
case '\n':
printf("\\n");
break;
case '\r':
printf("\\r");
break;
case 0:
printf("null char");
break;
default:
if(string[n] < ' ' || string[n] > 127)
{
printf("\\x%x", (unsigned)string[n]);
}
else
printf("'%c'", string[n]);
}
printf("\n");
}
}
return (0);
}
https://godbolt.org/z/afb3Ej7E9