java中的变量

public class learn {   //类名必须和文件名保持一致。

    public static void main(String[] args){

        System.out.println("This is my first Java programe.");

        System.out.println("This is a programe.");

    }

}

静态变量申明与使用

public class learn{

    static final double PI=3.1415926;

    static int age = 20;

    public static void main(String[] args){

        final int number;

        number = 1235;

        age = 22;

        System.out.println(number);

        System.out.println(age);

        System.out.println(PI);

    }

}

public class learn{

    static int times = 3;

    static int y=90;

    public static void main(String[] args){

        int times = 4;

        System.out.println(times);  // 局部变量在方法中有效

        System.out.println(exam001.y);  //静态变量调用

    }

}

public class learn{

    public static void main(String[] args){

        int a,b,c;

        a = 15;

        c=b=a+4;   //在Java中可以把赋值运算符连在一起使用，但实际开发中不建议这样写。

        System.out.println(a);

        System.out.println(c);

        System.out.println(b);

    }

}