++x is called preincrement while x++ is called postincrement.
int x = 5, y = 5;
System.out.println(++x); // outputs 6
System.out.println(x); // outputs 6
System.out.println(y++); // outputs 5
System.out.println(y); // outputs 6
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…