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Question

Enumeration e = session.getAttributeNames(); String key, value;
while( e.hasMoreElements() ) {
key = (String) e.nextElement();
value = (String) s.getAttribute( key );
out.print( key + value );
I'm not familiar with (String) usage, lines 3,4.
It's obvious what's happening, though. My questions follow.
1.) Why is the reserved word String in parentheses?
2.) What other reserved words could I use in its place?
3.) By deleting it, error says it found Object but required String.
In earlier code, I defined it as a String. What gives?
thanks,
[email protected]

Answer 1

the syntax (String) is called a CAST - it converts the 'type' of an object from one type to another.
in this case it's converting from the type Object to type String - this is basic Object talk - read any beginning
book on OO/Java and get a better understanding.
one must cast the object returned from the enumeration to a more usefull type - but you may find
that the code has run time errors - if the enumeration has other than Strings in it - for example
one could put a Boolean object in the enumeration and casting to a String will give a class cast exception
at run time.