14. Arrays Flashcards
Does an array object have a variable or a fixed size?
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Do we need to change the program source code in order to change the size of an array used by a program?
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Which of the following variable declarations are legal?
- int {} smallPrimes = {2, 3, 5, 7, 11, 13, 17, 19};
- int [] smallPrimes = [2, 3, 5, 7, 11, 13, 17, 19];
- int [] smallPrimes = {2, 3, 5, 7, 11, 13, 17, 19};
- int {} smallPrimes = [2, 3, 5, 7, 11, 13, 17, 19];
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How many in variables are created by the following code?
int[][] anArray = new int[4][];
for (int index = 0; index < anArray.length; index++)
anArray[index] = new int[index];
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How many references are involved in the following?
int[][] my2DArray = new int[5][4]
20
What set of indices does an array of ten elements have?
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Consider the following.
int[][] my2DArray = new int[5][4];
Which element is acces by my2DArray[4][1]?
- The first element in the last row.
- The second element in the last row.
- The first element in the penultimate row.
- The fourth element in the first row.
- The third element in the first row.
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How do we find the length of an array?
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What is the difference between and array variable containing null, and one containing a reference to an empty array?
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What does an ‘array of objects’ contain?
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What other variable do we need to support a partially filled array?
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What is the minimum size increase when extending an array? What is a good size increase?
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What is the difference between shallow and deep copies?
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How does linear search in a list work?
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Give three examples of a sort order on simple data, such as numbers or names.
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When using bubble sort for an array of length n, how many pair comparisons are needed worst case? (I.e. how many passes, and how many pairs on each pass?
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What is the essential difference between double division by zero and that of integer division?
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Which of the following expressions could produce an exception, where size and sum are int variables?
- size == 0 || sum / size >= 0
- sum / size < 10 && size != 0
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What is the most obvious example of accepting parameters of an array type?
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In what sense does a method never return an array?
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What is the return type of the round() method?
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How do we use Scanner to read every line of a file?
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What is the difference between format() and System.out.printf()?
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What does the split() method do?
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What happens if the item matching “%s” is not a string?
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What is the output by the following?
System.out.printf(“From %s to %s is %1.2f miles.%n”, “here”, “eternity”, 1.0/0);
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When talking about System.out.printf(), then what is the difference between right and left justification, and how do we obtain each one?
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When should we use a for-each loop? In particular, what can it not do?
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What are enum types used for?
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How do we use an enum type defined in another class?
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How do we write the type of an array which has a String base type?
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What benefits does class constants and a set if its choices have, compared with using the integer values directly?
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What are the dangers of class constant and a set of its choices approach?
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In what sense does an array type variable never contain and array?
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