java enmu 类型完整举例
时间: 2023-10-27 14:50:09 浏览: 42
当然,我很乐意回答这个问题。Java中的枚举(enum)类型是一组有限的命名常量。下面是一个完整的枚举类型例子:
public enum Planet {
MERCURY (3.303e+23, 2.4397e6),
VENUS (4.869e+24, 6.0518e6),
EARTH (5.976e+24, 6.37814e6),
MARS (6.421e+23, 3.3972e6),
JUPITER (1.9e+27, 7.1492e7),
SATURN (5.688e+26, 6.0268e7),
URANUS (8.686e+25, 2.5559e7),
NEPTUNE (1.024e+26, 2.4746e7);
private final double mass; // in kilograms
private final double radius; // in meters
Planet(double mass, double radius) {
this.mass = mass;
this.radius = radius;
}
public double mass() { return mass; }
public double radius() { return radius; }
// universal gravitational constant (m3 kg-1 s-2)
public static final double G = 6.67300E-11;
public double surfaceGravity() {
return G * mass / (radius * radius);
}
}
此枚举类型表示八个行星及其相关信息。每个行星都有其质量(以千克为单位)和半径(以米为单位)。在实例化时,它们都有一个类似这样的构造函数: Planet(double mass, double radius)。每个枚举常量都具有与其相关的值(如MERCURY中的3.303e+23和2.4397e6)。