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Can HashMap store null values?If yes, how many?
Can HashMap store null values?If yes, how many?What is singleton class? Give one example.Please describe the difference between 'int' and 'Integer',what is the purpose of 'Integer', where should we use 'Integer' vs 'int'?
sushilbehera
- Jan 29th, 2010
Yes HashMap can store null values. Any number of null values can be stored.Please note null can be stored multiple times as value however only one time as key.
fcasttro
- Mar 22nd, 2008
Map Won't allow duplicates, So It will accept one null value.HashMap map = new HashMap();map.put(null, null);map.put(null, null); map.put(null, null);After adding 3 null key / value pairs. It will...
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What is the diffrence between composition and aggrigation?
kim2kim
- Feb 1st, 2008
Aggregate is when one object contains other objects. Think of aggregate as "is a part of". Composition is when one object controls the life span of another object.
