Java Increment / Decrement Operators - How they behave, what's the functionality?

Question

It\'s been 3 days since I start to learn Java. I have this program and I don\'t understand code in main method with ++ and -- operator

Answer 1

These are called Pre and Post Increment / Decrement Operators.

x++;

is the same as x = x + 1;

x--;

is the same as x = x - 1;

Putting the operator before the variable ++x; means, first increment x by 1, and then use this new value of x

int x = 0; 
int z = ++x; // produce x is 1, z is 1


    int x = 0;
    int z = x++;  // produce x is 1, but z is 0 , 
                  //z gets the value of x and then x is incremented. 

Answer 2

++ and -- are called increment and decrement operators. They are shortcuts for writing x = x+1 (x+=1) / x = x-1 (x-=1). (assumed that x is a numeric variable)

In rare cases you could worry about the precedence of the incrementation/decrementation and the value the expression returns: Writing ++x it means "increment first, then return", whereas x++ means "return first, then increment". Here we can distinguish between pre- and post increment/decrement operators.