The instanceof operator tests the class of an object at runtime. : instanceof Operator « Operators « SCJP






//The left argument can be object reference, usually a variable or an array element.
//The right operand must be a class, interface, or array type. 


public class MainClass {
  public static void main(String[] argv) {
    MyClass myObject = new MyClass();

    if (myObject instanceof MyClass) {
      System.out.println("myobject is an instance of MyObject");
    }

  }
}

class MyClass {

}

class MyAnotherClass {
}
myobject is an instance of MyObject








2.7.instanceof Operator
2.7.1.instanceof operator determines whether or not a given object is an instance of a particular class.
2.7.2.The instanceof operator tests the class of an object at runtime.
2.7.3.Using instanceof operator in class hierarchy
2.7.4.You cannot use a java.lang.Class object reference.
2.7.5.You cannot use a String representing the name of the class as the right operand.
2.7.6.The right operand of instanceof may be an interface.
2.7.7.Using the instanceof operator to test whether a reference refers to an array.
2.7.8.This line is not legal: if (x instanceof [])
2.7.9.Determine whether an object is an array using the isArray() method of the Class class.
2.7.10.If the left argument of the instanceof operator is a null value, the instanceof test simply returns false;
2.7.11.The instanceof Operator: Objects always "know" what type they are.
2.7.12.instanceof is for object reference variables only
2.7.13.instanceof attempts to downcast
2.7.14.test whether the null reference is an instance of a class. This will always result in false.
2.7.15.instanceof Compiler Error
2.7.16.Operands and Results Using instanceof Operator