Does anyone have any idea why the if not be executed?

Question

if (strcmp(letra4, "[") == 0) {
  char string_sem_colchete[10];
  for(i=1; i<strlen(comando4)-1; i++)
  {
    string_sem_colchete[i-1] = comando4[i];
  }

  string_sem_colchete[i-1] = '\0';
  numero4 = atoi(string_sem_colchete);
  printf("%i", numero4);
}

In summary the variable letra4 is the first position of a string, if the character of that position is "[", it will execute that code within the if to remove the first and last character of that string and convert into int. The code works, the problem is that the IF appears not to be executed.

Answer 1

You just want to compare the first char? strcmp compares the entire string. It would only pass in if its string was only "[".

Compare only the first position: if (letra4[0] == '[')... This imagining that letra4 is either a vector or a pointer, because you left the mystery in the air right?

Answer 2

How does it mention that the variable letra4 is the first position of a string, I believe you want to compare chars. If this is the case, comparing the values directly should be sufficient (note that I am using single quotes, this denotes the type char and not string):

if (letra4 == '[') {

The comparison you’re trying to make with strcmp currently should receive two pointers (strings or char*) in your call. It would work if you were passing char* (just as an example, remember to allocate and release the memory used):

char* letra4 = "[";

Using pointers and not char, you can make the comparison with strcmp.

---

And your case string be a array of chars literal:

char letra4[20] = {/*...*/};

You can compare only the first position of your array:

if (letra4[0] == '[') {

I hope I’ve helped in some way.

Answer 3

If you are not entering the IF, I believe that 'letra4' is presenting another value. Try to put breakpoint and access the contents of this variable.

If you have any questions about strcmp doc': http://linguagemc.com.br/a-biblioteca-string-h/