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Ans. It's a Collections concrete class that provides implementation of a Double Ended queue that allows concurrent insertion, removal, and access operations that can be executed safely across multiple threads.
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Ans. This collections class has been implemented in such a manner that it can never throw ConcurrentModificationException. As it performs update and write operations by creating a new copy of ArrayList, It's slower compared to ArrayList.
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Ans. Exception thrown by the application is we try to access an element using an index which is not within the range of array i.e lower than 0 or greater than the size of the array.
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Though the following code will compile fine but will result in ClassCastException during runtime.
Fruit fruit = new Apple();
Banana banana = Banana(fruit); // ClassCastException
This code will not give compile time error as Banana and Fruit are related as Banana either extends or implement Fruit, So downcasting is acceptable. With this code we assume that the Fruit handler will have the Apple object at that point, violating which the code will throw the exception.
This exception can be avoided by following code.
Fruit fruit = new Apple();
if(fruit instanceOf Banana){
Banana banana = Banana(fruit); // ClassCastException
}
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Ans. DocLint Provide a means to detect errors in Javadoc comments early in the development cycle and in a way that is easily linked back to the source code.
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Ans. Before Unicode there were many language / country standards like ASCII , ISO , KOI and BIG 5. In order to accommodate multiple language letters and to overcome problems with using different multiple standards , a new language standard was developed i.e unicode system.
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As we haven't specified the type of TreeSet, it being evaluated with the first element insertion. Once it's identified that it's of type String and as no comparator has been defined, the comparison is done using the String compareTo method. String compareTo method compares the elements by the content / value.
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Ans. float is a native data type whereas Float is a class. A Float object will always take more memory than float variable as there are metadata overheads with the objects.
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Ans. Fail-fast iterators detect illegal concurrent modification during iteration and fail quickly and cleanly rather than risking arbitrary, non deterministic behavior at an undetermined time in future. Example could be of an Iterator failing if it smells ConcurrentModificationException.
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java collections queue deque concurrent collections
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Which of the following can throw ClassCastException ?
