练习

 

public class a {
    
    public static void main(String[] arg){
    //注释
        
        System.out.println("Hellow wold");
        String a=("我在这里");
        a=("他在这里");
        System.out.println(a);
        byte t=-128;
        System.out.println(t);
        short s=9999;
        System.out.println(s);
        int l=123;
        System.out.println(l);
        float h=123.54555547444F;    
        System.out.print(h);
        
    }
    
}