Java Example - Usage of instanceof Keyword
Java Examplesinstanceof is a binary operator in Java, similar to ==, >, < and other operators.
instanceof is a reserved keyword in Java. Its purpose is to test whether the object on its left is an instance of the class on its right, returning a boolean data type.
The following example creates the displayObjectClass() method to demonstrate the usage of the Java instanceof keyword:
Main.java file code:
/*
author by example.com
Main.java
*/
import java.util.ArrayList;
import java.util.Vector;
public class Main {
public static void main(String[] args) {
Object testObject = new ArrayList();
displayObjectClass(testObject);
}
public static void displayObjectClass(Object o) {
if (o instanceof Vector)
System.out.println("The object is an instance of the java.util.Vector class");
else if (o instanceof ArrayList)
System.out.println("The object is an instance of the java.util.ArrayList class");
else
System.out.println("The object is" + o.getClass() + "an instance of the class");
}
}
The output of the above code is:
对象是 java.util.ArrayList 类的实例Other Extensions