Essentially ‘b = a’ in the second example is equivalent to ‘b = &a[0]’ or assigning an array to a pointer. This is because if you use an array in an expression

Essentially ‘b = a’ in the second example is equivalent to ‘b = &a[0]’ or assigning an array to a pointer. This is because if you use an array in an expression, it’s value is (most of the time) a pointer to the array’s first element. But the left element is not an expression, therefore it is referring to b the array. Example one works because no arrays are referred to in the expression side, so this shorthand so to speak is avoided. Arrays can be a painful edge in C, for example variable length arrays are hair pulling.