What is the output sequence?

Question

int a=0;
cout <<a++<<a++<<a++<<endl;
Why the output is 210? Why it is not 012?

Answer 1

In complex cascading increment/decrement couts like this, statement is evaluated right to left.
So starting from right,
a++ displays 0
a=1
a++ displays 1
a=2
a++ displays 2
a=3
Now, display will be done as usual (left to right).
So output is
210