expression - Java modulus operator - why is the result unexpected? -

i understand in modulus 17/12 = 5.

why 4+17 % 2-1 value 4, , (4+17) % 2-1 value 0?

operator precedence. % evaluated first, so

4 + 17 % 2 - 1 

is equivalent to

4 + (17 % 2) - 1 

17%2 == 1 yields 4+1-1 equals 4

when place brackets there, change order of evaluation:

(4+17) % 2 - 1 

is equivalent to

21 % 2 - 1 

which again, because of % having higher precendence -, yields

1 - 1 

which 0