| 9. 18. 2. 创建HashSet |
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The HashSet class provides four constructors broken into two sets. The first three constructors
create empty sets of varying sizes: |
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public HashSet()
public HashSet(int initialCapacity)
public HashSet(int initialCapacity, int loadFactor)
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When creating any collection, it is always best to have the local variable be of the interface type, |
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For easier to change the set to a TreeSet or some other set implementation. |
The fourth constructor acts as a copy constructor. |
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public HashSet(Collection col)
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If the original collection had duplicates, only one of the duplicates will be in the final created set. |