4.1 | Given the following declaration, which expression returns the size of the array, assuming the array has been initialized ? int[] array; Select the one correct answer. -
array[].length() -
array.length() -
array[].length -
array.length -
array[].size() -
array.size() | 4.2 | Is it possible to create arrays of length zero? Select the one correct answer. -
Yes, you can create arrays of any type with length zero. -
Yes, but only for primitive data types. -
Yes, but only for arrays of object references. -
No, you cannot create zero-length arrays, but the main() method may be passed a zero-length array of String references when no program arguments are specified. -
No, it is not possible to create arrays of length zero in Java. | 4.3 | Which one of the following array declaration statements is not legal? Select the one correct answer. -
int []a[] = new int [4][4]; -
int a[][] = new int [4][4]; -
int a[][] = new int [][4]; -
int []a[] = new int [4][]; -
int [][]a = new int [4][4]; | 4.4 | Which of these array declaration statements are not legal? Select the two correct answers. -
int[] i[] = { { 1, 2 }, { 1 }, {}, { 1, 2, 3 } }; -
int i[] = new int[2] {1, 2}; -
int i[][] = new int[][] { {1, 2, 3}, {4, 5, 6} }; -
int i[][] = { { 1, 2 }, new int[ 2 ] }; -
int i[4] = { 1, 2, 3, 4 }; | 4.5 | What would be the result of attempting to compile and run the following program? // Filename: MyClass.java class MyClass { public static void main(String[] args) { int size = 20; int[] arr = new int[ size ]; for (int i = 0; i < size; ++i) { System.out.println(arr[i]); } } } Select the one correct answer. -
The code will fail to compile because the array type int[] is incorrect. -
The program will compile, but will throw an ArrayIndexOutOfBoundsException when run. -
The program will compile and run without error, but will produce no output. -
The program will compile and run without error and will print the numbers 0 through 19. -
The program will compile and run without error and will print twenty times. -
The program will compile and run without error and will print null twenty times. | 4.6 | Given the following program, which statement is true? class MyClass { public static void main(String[] args) { String[] numbers = { "one", "two", "three", "four" }; if (args.length == 0) { System.out.println("no arguments"); } else { System.out.println(numbers[ args.length ] + " arguments"); } } } Select the one correct answer. -
The program will fail to compile. -
The program will throw a NullPointerException when run with zero program arguments. -
The program will print "no arguments" and "two arguments" when called with zero and three program arguments, respectively. -
The program will print "no arguments" and "three arguments" when called with zero and three program arguments, respectively. -
The program will print "no arguments" and "four arguments" when called with zero and three program arguments, respectively. -
The program will print "one arguments" and "four arguments" when called with zero and three program arguments, respectively. | 4.7 | What would be the result of trying to compile and run the following program? public class DefaultValuesTest { int[] ia = new int[1]; boolean b; int i; Object o; public static void main(String[] args) { DefaultValuesTest instance = new DefaultValuesTest(); instance.print(); } public void print() { System.out.println(ia[0] + " " + b + " " + i + " " + o); } } Select the one correct answer. -
The program will fail to compile because of uninitialized variables . -
The program will throw a java.lang.NullPointerException when run. -
The program will print " 0 false NaN null ". -
The program will print " 0 false 0 null ". -
The program will print " null 0 0 null ". -
The program will print " null false 0 null ". | |