练习5
import static net.mindview.util.Print.print;
public class TestObject_5 {
static void showMsg(Dog dog){
print(dog.name+" is shouting "+dog.says);
}
public static void main(String[] args) {
Dog spot = new Dog();
Dog ruff = new Dog();
spot.name = "Spot";
spot.says = "Ruff!";
ruff.name = "scruffy";
ruff.says = "Wurf!";
showMsg(spot);
showMsg(ruff);
}
}
练习6
equals() 用于除基本类型外的对象
八大基本类型：
char / boolean / byte / short / int / long / float / double
import static net.mindview.util.Print.print;
public class TestObject_6 {
static void showMsg(Dog dog) {
print(dog.name + " is shouting " + dog.says);
}
public static void main(String[] args) {
Dog spot = new Dog();
spot.name = "Spot";
spot.says = "Ruff!";
Dog doggy = new Dog();
doggy = spot;
print("------- == -------");
print(doggy == spot);
print("------- equals -------");
print(doggy.equals(spot));
print()
showMsg(doggy);
showMsg(spot);
}
}
练习7
- 与或非操作只能用于布尔值
- 如果在应用string类型的地方使用了布尔值，布尔值会自动转换成适当的文本形式
import java.util.Random;
public class ThrowCoins {
public static void main(String[] args) {
Random random = new Random();
int coin = random.nextInt();
if (coin % 2 == 1)
System.out.println("HEAD");
else
System.out.println("FLOWER");
}
}
练习8
- 16进制前缀 0x
- 8进制前缀 0
public class LongValues {
public static void main(String[] args) {
long hexadecimal = 0xffff;
long octal = 07777L;
System.out.println(hexadecimal);
System.out.println(octal);
System.out.println("--------Long.toBinaryString()-------");
System.out.println("hexadecimal = " + Long.toBinaryString(hexadecimal));
System.out.println("otcal = " + Long.toBinaryString(octal));
}
}
练习9
import static net.mindview.util.Print.print;
public class MinMax {
public static void main(String[] args) {
print("--------Float--------");
print("Min = " + Float.MIN_VALUE);
print("Max = " + Float.MAX_VALUE);
print("--------Double-------");
print("Min = " + Double.MIN_VALUE);
print("Max = " + Double.MAX_VALUE);
}
}