If x=8 and y=7 then x++ then x+=y-- value of x comes 16 but how???

Answer 1

x = 8
y = 7
x++ // same as x = x + 1
x += y-- // same as x = x + y and then y = y - 1

when you have
x += --y
it will be the same as
x = x + (y = y - 1)

Answer 2

Okkk thanks