i++ returns i instead of i++ [duplicate]

These are the pre- and post-increment operators. This behavior is exactly correct.

• i++ returns the original value.
• ++i returns the new value.

When you do i++ the incrementation doesn't happen until the next instruction. It's called a post increment.

++i will print 1
i++ will print 0 

System.out.println(i++);

It should first print value of i then increment the i. Its post order increment.

• i++ -> post order increment
• ++i -> pre order increment

i++ means return i, then increment. Hence ++ after i.

++i means increment i, then return. Hence ++ in front of i

• i++ => evaluation then increment;
• ++i => increment then evaluation.

Think about a for loop - i is incremented after every iteration.

The ++ after the variable defines a post-increment operation. This means that after you are done executing everything else on the line, then i is increased. If you used ++i the variable would be incremented before it is printed

As you can find here: http://docs.oracle.com/javase/tutorial/java/nutsandbolts/op1.html there are two incrementing operators: i++ and ++i. ++i does what you thought i++ would do. i++ increments the value after usage for other purposes (look into the link for more details)

Because the value given to the System.out.println(i++);is assigned 0 first then it is incremented. if you will attempt to do System.out.println(++i); then it will display 1 to you.