//方法的演示
public class MethodDemo {
public static void main(String[] args) {
say();
say();
System.out.println(Math.sqrt(25));
//sayHi();//编译错误,有参必须传参
//sayHi(250);//编译错误,参数类型不匹配
sayHi("zhangsan");// String name = "zhangsan"
sayHi("lisi");// String name = "lisi"
sayHi("wangwu");//String name = "wangwu"
int a = getNum();//getNum()的值就是return后的那个数
System.out.println(a);//88
double b =plus(55,66);//double a =55,double b=66
System.out.println(b);
// double num1 = 5.5,num2 = 6.6;
// double b = plus(num1,num2);//double a =5.5,double b =6.6
// System.out.println(b);
System.out.println("over");
}
//有参有返回值
public static double plus(double a,double b){
double sum = a + b;
return sum;//返回sum中的那个数
//return a+b;//返回a+b的值
}
//无参有返回值
public static int getNum(){
//return;//编译错误,必须返回一个值
//return 8.88;//编译错误,返回值类型不匹配
return 88;//1.结束方法的执行,2.返回一个结果给调用方
}
//有参无返回值---有参可以使用方法更灵活
public static void sayHi(String name){
System.out.println("大家好,我叫"+name);
return;//1.结束方法的执行
}
//无参无返回值
public static void say(){
System.out.println("大家好,我叫WKJ");
}
}