instanceof vs isInstance(Object obj)
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Posted By:   Ramu_G
Posted On:   Sunday, August 6, 2006 12:24 AM

Please someone help me how to use these two.



what are the differences? it will be better if sample code can be provided.


Thanks

Re: instanceof vs isInstance(Object obj)

Posted By:   Amir_Pashazadeh  
Posted On:   Tuesday, August 8, 2006 01:41 PM


First difference:

instanceof is a reserved word of Java, but isInstance() is a method of java.lang.Class.



Other differences:

you could use instanceof on types (which are known on compile time), and isInstance() could only be called on an instance fo java.lang.Class.



if (obj instanceof MyType) {
...
}


if (MyType.class.isInstance(obj)) {
...
}




so you can have dynamism using isInstane() like this:


Class x = Integer.class;

if (x.isInstance(obj)) {
...
}

x = String.class;

if (x.isInstance(obj)) {
...
}


as you see you could check the type of an object with an unknown class during compile time!

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