1、打开IDEA或其他开发工具
2、编写判断数据类型Demo。代码如下：
public class Test {
public static void main(String[] args) {
int i =1;
double d =2d;
float f = 1.3f;
String s = "str";
Object[] arr =new Object[]{i,d,f,s};
for (int j =0;j<arr.length;j++){
if(arr[j] instanceof Integer){
System.out.println(arr[j]+" is Integer");
}
if(arr[j] instanceof Double){
System.out.println(arr[j]+" is Double");
}
if(arr[j] instanceof Float){
System.out.println(arr[j]+" is Float");
}
if(arr[j] instanceof String){
System.out.println(arr[j]+" is String");
}
}
}
}
3、运行Demo，右击Run xx或者Debug xx .
4、查看运行结果
