CS 4A: Chapter 7 - 1D Arrays
An array can be used as:
- a local variable - a return value - a parameter
How can you initialize an array of two characters to 'a' and 'b'?
- char[] charArray = {'a', 'b'}; - char[] charArray = new char[]{'a', 'b'};
Which of the following declarations are correct?
- int[] list = {1, 2, 3, 4}; - int[] list = new int[]{1, 2, 3, 4};
Which of the following is the correct header of the main method?
- public static void main(String[] args) - public static void main(String args[]) - public static void main(String[] x) - public static void main(String x[])
Assume int[] scores = {1, 20, 30, 40, 50}, what value does java.util.Arrays.binarySearch(scores, 3) return?
-2
Suppose int[] numbers = new int[10], what is numbers[0]?
0
Assume int[] scores = {1, 20, 30, 40, 50}, what value does java.util.Arrays.binarySearch(scores, 30) return?
2
Use the selectionSort method presented in this section to answer this question. Assume list is {3.1, 3.1, 2.5, 6.4, 2.1}, what is the content of list after the first iteration of the outer loop in the method?
2.1, 3.1, 2.5, 6.4, 3.1
If you declare an array double[] list = {3.4, 2.0, 3.5, 5.5}, the highest index in array list is ________.
3
Assume int[] t = {1, 2, 3, 4}. What is t.length?
4
How many elements are in array double[] list = new double[5]?
5
An array variable can be declared and redeclared in the same block. True/False
False
Binary search can be applied on an unsorted list. True/False
False
The array size is specified when the array is declared. True/False
False
The element in the array must be of a primitive data type. True/False
False
What is the correct term for numbers[99]?
Indexed variable
Which correctly creates an array of five empty Strings?
String[] a = {"", "", "", "", ""};
Analyze the following code. int[] list = new int[5]; list = new int[6];
The code can compile and run fine. The second line assigns a new array to list.
When you pass an array to a method, the method receives ________.
The reference of the array
When you return an array from a method, the method returns ________.
The reference of the array
The array index of the first element in an array is 0. True/False
True
The arraycopy method does not allocate memory space for the target array. The target array must already be created with memory space allocated. True/False
True
You can use the operator == to check whether two variables refer to the same array. True/False
True
How can you get the word "abc" in the main method from the following call? java Test "+" 3 "abc" 2
args[2]
________ declares an array of char.
char[] chars
Which of the following is correct to create an array?
int[] m = {1, 2, 3};
The ________ method sorts the array scores of the double[] type.
java.util.Arrays.sort(scores)
The reverse method is defined in this section. What is list1 after executing the following statements? int[] list1 = {1, 2, 3, 4, 5, 6}; int[] list2 = reverse(list1);
list1 is 1 2 3 4 5 6
Use the selectionSort method presented in this section to answer this question. What is list1 after executing the following statements? double[] list1 = {3.1, 3.1, 2.5, 6.4}; selectionSort(list1);
list1 is 2.5 3.1, 3.1, 6.4
Suppose a method p has the following heading: public static int[] p() What return statement may be used in p()?
return new int[]{1, 2, 3};
Assume the signature of the method xMethod is as follows. public static void xMethod(double[] a) Which of the following could be used to invoke xMethod?
xMethod(new double[2]);