Can't understand this way to calculate the square of a number

Can't understand this way to calculate the square of a number

c arrays pointers c99 variable-length-array

arrays

How does the compiler allocate memory without knowing the size at compile time?

c arrays memory c99 variable-length-array

arrays

Why is int x[n] wrong where n is a const value?

c arrays constants c99

arrays

Passing a multidimensional variable length array to a function

c arrays c99

arrays

Literal string initializer for a character array

c string pointers arrays c99

arrays

What are those strange array sizes [*] and [static] in C99?

c arrays c99 function-prototypes c11

arrays

C - Implementing fast push of many elements to the end of array

c arrays optimization c99

arrays

Best way to compare two int arrays of the same length?

c arrays compare int c99

arrays

Casting pointer to memory buffer to pointer to VLA

c arrays pointers c99

arrays

variable length array declaration not allowed in OpenCL - why?

arrays memory memory-management opencl c99

arrays

Variable Length Arrays in C++14?

c++ arrays visual-studio-2015 c99 variable-length-array

arrays