求学，哪位大Shen救救孩子！！

这是一题还是四题？
2、3是小题吗

public class Test {
    public static void main(String[] args){
       int n1=2;
       double n2=2;
       if (n1==n2){
           System.out.println("n1等于n2");
       }else{
           System.out.println("n1不等于n2");
           if (n1>n2) {
               System.out.println("n1大于n2");
           }else{
               System.out.println("n1小于n2");
           }
       }



       String str="ABcsdDg";
        System.out.println("全部转大写："+str.toUpperCase());
        System.out.println("全部转小写："+str.toLowerCase());
        System.out.println("截取字符串前三位："+str.substring(0,3));



        int a=1,b=2;
        if (a>b){
            System.out.println(a+"大于"+b);
        }else if (a<b){
            System.out.println(a+"小于"+b);
        }else{
            System.out.println(a+"等于"+b);
        }



        if (n1==n2){
            System.out.println(n1+"等于"+n2);
        }else{
            if (n1>n2) {
                System.out.println(n1+"大于"+n2);
            }else{
                System.out.println(n1+"小于"+n2);
            }
        }
    }
}