• java基础1


    第一章:java语言基础;

    //第一个程序HelloWorld.java

    package foxe;

    public class HelloWorld {

    /**
    * @param args
    */
    public static void main(String[] args) {
    System.out.println("Hello,World!");
    // TODO Auto-generated method stub

    }

    }

    //第二个程序HelloWorld_Applet .java

    package foxe;
    import java.awt.Graphics;
    import javax.swing.JApplet;
    public class HelloWorld_Applet extends JApplet{

    public void paint(Graphics g) {
    g.drawString("Hello World!", 25, 25);


    }

    }

    //第三个程序for ,while,do-while         sum.java

    package foxe;

    public class Sum {

    /**
    * @param args
    */
    public static void main(String[] args) {
    int i=1,n=10,sum1=0,sum2=0,sum3=0;
    //for circulation
    for(i=1;i<=n;i++){
    sum1=sum1+i;

    }
    System.out.println("for sum is :"+sum1);
    i=1;
    while(i<=n){
    sum2=sum2+i;
    i++;
    }
    System.out.println("while sum is :"+sum2);
    i=1;
    do{
    sum3=sum3+i;
    i++;
    }while(i<=n);
    System.out.println("do-while sum is :"+sum3);


    }

    }

    第二章:类和对象

    //第四个程序 参数传递ParameterTest .java

    package foxe;

    class Point{
    int x=70;
    int y=80;
    }
    class Circle{
    int x=5,y=6;
    Point point ;
    void setXY(int x1,int y1){
    x1=x;
    y1=y;
    }
    void setPoint (Point ref){
    ref.x=x;
    ref.y=y;

    }
    }
    public class ParameterTest {
    //pass parameter test

    /**
    * @param args
    */

    public static void main(String[] args) {
    Circle p=new Circle();
    int xValue=-1,yValue=-1;
    System.out.println("value pass:");
    p.setXY(xValue, yValue);
    System.out.println("xValue="+xValue+",yValue="+yValue);

    Point point=new Point();
    p.setPoint(point);
    System.out.println("address pass:");
    System.out.print("point.x="+point.x+",point.y="+point.y);

    }
    }

    //第五个程序 类变量和类方法与实例变量和实例方法;

    package foxe;
    class Member{
    static int classVar;//类变量
    int instanceVar;//实例变量
    static void setClassVar(int i){
    classVar=i;

    //instanseVar=i;类方法不能访问实例变量

    }
    static int getClassVar(){//类方法
    return classVar;

    }
    void setInstanceVar(int i){//实例方法
    classVar=i;//实例方法可以访问类变量
    instanceVar=i;

    }
    int getInstanceVar()
    {
    return instanceVar;

    }

    }

    public class MemberTest {


    public static void main(String[] args) {
    Member m1=new Member();
    Member m2=new Member();
    m1.setClassVar(1);
    m2.setClassVar(2);
    System.out.println("m1.classVar="+m1.getClassVar()+",m2.classVar="+m2.getClassVar());

    m1.setInstanceVar(11);
    m2.setInstanceVar(22);
    System.out.println("m1.InstanceVar="+m1.getInstanceVar()+",m2.InstanceVar="+m2.getInstanceVar());

    Member.classVar=3;
    System.out.println("m1.ClassVar="+m1.getClassVar()+",m2.ClassVar="+m2.getClassVar());
    System.out.println("ClassVar="+Member.getClassVar());

    }

    }

    ///独立代码片断;

    class EnclosingClass{
    static class StaticNestedClass{//静态嵌套类
    /……/
    }
    class InnerClass{//内部类
    /……/
    }
    }

    //第六个程序  静态嵌套类的使用

    package foxe;

    class Outer{
    int a;
    public static class Inner{
    public void aMethod(){
    Outer out=new Outer();
    out.a++;System.out.print("this is an inner method");
    }

    }
    }

    public class NestedClass {

    public static void main(String[] args) {
    Outer.Inner inner=new Outer.Inner();
    inner.aMethod();
    }

    }

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  • 原文地址:https://www.cnblogs.com/fooxer/p/3653518.html
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