Why does this use of comma work in a expression but fail in a declaration?

Question

Am from high level OOP languages C# and Java and recently started scratching my head in C. I feel C a bit weird as equally as one feels JS is. So want to clarify below:

Answer 1

i = 0,1,2; 

This is assignment, which is equivalent to:

(i = 0), 1, 2;

The comma operator(which has the lowest precedence) evaluates all operands from left to right, first the assignment i = 0, then the expression 1 and 2 and throws the result away.

The second example

int i=0,1,2;  

is initialization. Compare it with the legal initialization int i = 0, j = 0;.

It works if you use:

int i=(0,1,2);