instanceof

    import java.lang.reflect.*; 
     
    class ClassA{ 
        private int a; 
        private String b; 
        private int[] c; 
        ClassA(Object temp){ 
            if(temp instanceof Integer){//判断输入的是整型 
                a = Integer.parseInt(temp.toString()); 
                System.out.println("this is an <"+ temp.getClass().getName() +"> type. Integer value=" + a); 
                 
            }else if(temp instanceof String){//判断输入的是字符串 
                b = temp.toString(); 
                System.out.println("this is a <"+ temp.getClass().getName() +"> type. String value=" + b); 
            }else if(temp instanceof int[]){//判断输入的是整型数组 
                int n = Array.getLength(temp); 
                int[] c = new int[n]; 
                for(int i = 0;i < n; i++){ 
                    c[i] = Array.getInt(temp,i); 
                } 
     
                System.out.print("this is an <"+ temp.getClass().getName() +"> type. Int[]array value="); 
                for(int i = 0;i < n; i++){ 
                    System.out.print(c[i] + ", "); 
                } 
                System.out.println(); 
            } 
        } 
         
        public static void main(String[] args){ 
            ClassA test1= new ClassA(12); 
            ClassA test2= new ClassA("OK"); 
             
            int tmp[] = {1,2}; 
            ClassA test3= new ClassA(tmp); 
        } 
    }