Hello World

 

Helloworld
package HelloWorld;

public class Main {

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

}

int类型的1+1

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner Ind = new Scanner(System.in);
        int a=Ind.nextInt();
        int b=Ind.nextInt();
        System.out.println(a+b);
    }

}

数组的定义与使用
        Scanner Ind = new Scanner(System.in);
        int[] a=new int[10];///一维数组
　　　　　///int[][] a = new int[20][20] 二维数组的定义
        a[0]=Ind.nextInt();
        a[1]=Ind.nextInt();
        System.out.println(a[0]+a[1]);

package BuyCar;

public class Tcar {///建造一个汽车类   并且进行调用
    public static void main(String[] args) {
        Car c1 = new Car();
        c1.info();
        c1.info("baoma",4);
        System.out.println(c1.getName());
        c1.info();
        
        
        Factory f=new Factory();
        Car c2=f.newCar();
        c2.info();
        Car c3=f.newCar("aodi", 6);
        c3.info();
        f.chakan(c3);
    }
}
class Factory{
    public Car newCar() {
        return new Car();
    }
    public Car newCar(String s,int a) {
        Car ans=new Car();
        ans.name=s;
        ans.wheel=a;
        return ans;
    }
    public void chakan(Car a) {
        a.info();
    }
}
class Car {
    String name;///属性
    int wheel;
    public void info() {///方法
        System.out.println("name:"+name+",wheel:"+wheel);
    }
    public void info(String str,int a) {
        name=str;wheel=a;
    }
    public String getName() {
        return name;
    }
}  输出：

name:null,wheel:0
baoma
name:baoma,wheel:4
name:null,wheel:0
name:aodi,wheel:6
name:aodi,wheel:6

package AddSum;///JDK新特性之可变个数的形参的方法

public class Add {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Add sum=new Add();
        System.out.println(sum.getSum(1,2,3,4));
        System.out.println(sum.getStr("qwe","asd","zxcc"));

    }
    public int getSum(int ... args){
        int sum=0;
        for(int i=0;i<args.length;i++)
            sum+=args[i];
        return sum;
    }
    public String getStr(String ... s) {
        String str=new String();for(int i=0;i<s.length;i++)
            str=str+s[i];
        return str;
    }
}

10
qweasdzxcc