day06_方法_20150806

package day06;
//方法的演示
public class MethodDemo {
	public static void main(String[] args) {
		//say();
		
		//sayHi(); //编译错误，必须传參数
		//sayHi(8); //编译错误，參数类型不匹配
		
		//sayHi("zhangsan"); //String name="zhangsan"
		//sayHi("lisi"); //String name="lisi"
		//sayHi("wangwu"); //String name="wangwu"
		
		//int num = getNum();
		//System.out.println(num); //88
		
		//double d = plus(5,6); //double num1=5,double num2=6
		//System.out.println(d); //11
		//double a = 5.5;
		//double b = 4.4;
		//double dou = plus(a,b); //double num1=5.5,double num2=4.4
		//System.out.println(dou);
		
		a(); //方法的嵌套调用
		
		System.out.println("over");
	}
	
	public static void a(){
		System.out.println(111);
		b();
		System.out.println(222);
	}
	public static void b(){
		System.out.println(333);
		c();
	}
	public static void c(){
		System.out.println(444);
	}
	

	//有參有返回值
	public static double plus(double num1,double num2){
		//double num = num1+num2;
		//return num; //返回的不是num，而是num里面那个数
		return num1+num2; //返回的是num1+num2的值
	}
	
	//无參有返回值
	public static int getNum(){
		//return; //编译错误。必须返回一个值
		//return 5.55; //编译错误，返回值类型不匹配
		return 88; //1.结束方法的运行  2.返回结果(250)给调用方
	}
	
	//有參无返回值
	public static void sayHi(String name){
		System.out.println("大家好，我叫"+name);
		return; //1.结束方法的运行
	}
	
	//无參无返回值
	public static void say(){
		System.out.println("大家好，我叫WKJ");
	}
	
}