4. 案例4-1,打印不同的图形(正方形与菱形,使用抽象类)。
abstract class shape{
abstract void fang();
abstract void leng();
}
class run extends shape {
public void fang() {
int x = 4;
for (int i = 0; i <= 4; i++) {
for (int j = 0; j <= 4; j++) {
System.out.print("*");
}
System.out.println();
}
}
public void leng() {
for (int i = 1; i <= 4; i++) {
for (int j = 1; j <= 4 - i; j++) {
System.out.print(" ");
}
for (int k = 1; k <= 2 * i - 1; k++) {
System.out.print("*");
}
System.out.println();
}
for (int i = 3; i >= 1; i--) {
for (int j = 1; j <= 4 - i; j++) {
System.out.print(" ");
}
for (int k = 1; k <= 2 * i - 1; k++) {
System.out.print("*");
}
System.out.println();
}
}
}
public class driver {//自定义的driver类
public static void main(String[] args) {
run r = new run();
r.fang();
r.leng();
}
}