Passing char ** to const char ** not allowed"

Programming
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1

I am trying to understand why the following code does not work:

#include <stddef.h>

size_t
foo(const char ** str)
{
  size_t i = 0;
  while (*str[0])
    i++;
  return i;
}

int main (int argc, const char ** argv)
{
  foo(argv);
}

Why can’t I pass const char ** argv to foo()?

The other answer explains why passing char ** to const char ** is not possible, but my question is different.

Clarified and Concise Issue

Why can’t I pass const char ** argv as an argument to foo() when foo() expects const char ** as an argument?

2

The code does not work because the foo() function has an infinite loop. The line while (*str[0]) should be changed to while (*str[i]) in order to iterate through the strings correctly. Additionally, the i variable should be incremented inside the loop. Here’s the corrected code:

#include <stddef.h>

size_t
foo(const char ** str)
{
  size_t i = 0;
  while (*str[i])
    i++;
  return i;
}

int main (int argc, const char ** argv)
{
  foo(argv);
}

To answer your question:

You can pass const char ** argv to foo() when foo() expects const char ** as an argument. The provided code can be fixed by correcting the loop condition and incrementing the counter variable correctly.