I++ 是先取出i的值，然后參與運(yùn)算+1。
public
class Welcome {
????public
static
void main(String[] args) {
????????int
i=3;
????????System.out.println(i++);
????????}
}
輸出為3
++i是先+1，然后參與運(yùn)算。
public
class Welcome {
????public
static
void main(String[] args) {
????????int
i=3;
????????System.out.println(++i);
????????}
}
輸出為4
下面這個(gè)例子說明了這個(gè)道理
public
class Welcome {
????public
static
void main(String[] args) {
????????int i=3;
????????int count=(i++)+(i++)+(i++);
????????System.out.println(i);
????????System.out.println(count);
????????}
}
輸出為6和12，i取了3次是6，count是3+4+5=12
public
class Welcome {
????public
static
void main(String[] args) {
????????int
i=3;
????????int count=(++i)+(++i)+(++i);
????????System.out.println(i);
????????System.out.println(count);
????????}
}
輸出為6和15，i取了3次是6，count是4+5+6=15