摘要：
public class Datetime { public static void main(String args[]){ java.util.Date current=new java.util.Date(); java.text.SimpleDateFormat sdf=new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String c=sdf.format(current); System.out.println(c); }} 阅读全文
摘要：
public class SquareEquation1{double a,b,c;double root1,root2;boolean boo;public SquareEquation1(double a,double b,double c){this.a=a;this.b=b;this.c=c;if(a!=0){boo=true;}else{boo=false;}}public void getRoots(){if(boo){System.out.println("是一元二次方程");double disk=b*b-4*a*c;if(disk>=0){root1 阅读全文
摘要：
import java.util.Date;public class Example4_13{public static void main(String args[]){Date date=new Date();System.out.printf("本地机器的时间：\n%s",date);}} 阅读全文
摘要：
package tom.jiafei;class Tom{void speak(){System.out.println("Tom类在tom.jiafei包中");}}public class Xuhui{public static void main(String args[]){Tom cat=new Tom();cat.speak();System.out.println("Xuhui类也在tom.jiafei包中");}} 阅读全文
摘要：
package tom.jiafei;class Tom{void speak(){System.out.println("Tom类在tom.jiafei包中");}}public class Example4_12{public static void main(String args[]){Tom cat=new Tom();cat.speak();System.out.println("Example4_12类也在tom.jiafei包中");}} 阅读全文
摘要：
public class Tom2{int leg;Tom2(int n){this.cry();leg=n;this.cry();}void cry(){System.out.println("我是Tom，我现在有"+leg+"条腿");}public static void main(String args[]){Tom2 cat=new Tom2(4);}} 阅读全文
摘要：
class People{double getArea(double x,int y){return x*y;}int getArea(int x,double y){return (int)(x*y);}double getArea(float x,float y,float z){return (x*x+y*y+z*z)*2.0;}}public class Example4_10{public static void main(String args[]){People zhang=new People();System.out.println("面积："+zhang 阅读全文