Different way of accessing array elements in C

Question

I am a teaching assistant for a C programming course, and I came across the following line of C code:

char str[] = \"My cat\'s name is Wiggles.\";
printf(\"%         


        

Answer 1

It's a funky syntax for sure, but...

str[5] would mean *(str+5)

And

5[str] would mean *(5+str)

Answer 2

Perfectly valid C. From Wikipedia:

Similarly, since the expression a[i] is semantically equivalent to *(a+i), which in turn is equivalent to *(i+a), the expression can also be written as i[a] (although this form is rarely used).

Wacky, but valid.