方法的重载
条件:
例:
public static void main(String[] args) {
Demo03 demo03 = new Demo03();
//System.out.println(demo03.plus(1, 2));
//System.out.println(demo03.plus(1, 2, 3));
demo03.plus(1.0, 2.0, 3.0);
double[] array = {1,2,3,4,5,6};
double result = demo03.plus(array);
System.out.println(result);
}
public int plus(int a, int b) {
return a + b;
}
public int plus(int a, int b, int c) {
return a + b + c;
}
public double plus(double a, double b) {
return a + b;
}
public double plus(double a, double b, double c) {
System.out.println("111");
return a + b + c;
}
//注意:可以传递独立的多个参数,也可以传递数组
public double plus(double... a) {
System.out.println("222");
double sum = 0;
for (double d : a) {
sum += d;
}
return sum;
}
//注意:无法和可变参构成重载
// public double plus(double[] a) {
// double sum = 0;
// for (double d : a) {
// sum += d;
// }
// return sum;
// }
构造方法
1.区别于普通方法
2.作用
3.注意
例:
public class Dog {
//1.private修饰的变量,只能在本类中使用
//在外部无法随意修改变量值
private String nickname;
private String type;
private char sex;
private byte age;
public Dog() {
}
public Dog(String nickname, String type, char sex, byte age) {
//2.在有参构造内部做参数的合法校验
this.nickname = nickname.equals("吴青山") ? "吴绿山" : nickname;
this.type = type;
this.sex = sex;
this.age = age < 0 ? 0 : age;
}
}