Java One-Dimensional Arrays: Traversal and Algorithms Online Quiz Questions

A Java array has length 5. Which range contains all and only its valid indices?

True or false: After executing for (int value : values) { value = value * 2; }, the elements of the int[] values array have been doubled.

What does countEven return for the array {12, 7, 19, 4, 10}?

Select all statements that are correct about empty Java arrays.

True or false: A method that searches for a target index can return -1 to indicate that the target does not occur in the array.

What is the average of the elements in {12, 7, 19, 4, 10}? Enter the exact decimal value; no rounding tolerance is allowed.

Which initialization is the safest starting point for finding the maximum of a known nonempty int[] values array?

Select all tasks for which an indexed for loop is an appropriate choice when processing a one-dimensional array.

Explain how this method works and determine its return value for {3, -2, 5, 0}:

public static int sumPositive(int[] values) { int total = 0; for (int value : values) { if (value > 0) { total += value; } } return total; }

For int[] values = new int[4];, which array access is invalid?

True or false: If values is an int[], then the expression values[2] has type int and refers to one element rather than the entire array.

An array is created with length 7. Which range contains exactly all of its valid indices?

What happens when Java executes the declaration int[] scores; by itself?

True or false: In a loop that accesses values[index], using index <= values.length is safe for traversing every element of the array.

True or false: A linear search that returns true immediately when it finds the target can avoid examining elements after the first match.

What exact Java exception class name is caused by evaluating values[values.length]?

Which statement correctly declares and creates an integer array with exactly four elements?

A method is guaranteed to receive a nonempty int[] values and must return its maximum. Which initialization is the most generally reliable before traversing the remaining elements?

What Java attribute gives the number of elements in an array?

What is printed by this Java code?

int[] values = {1, 2, 3, 4};
int product = 1;
for (int value : values) {
product *= value;
}
System.out.println(product);

After this code executes, what is the contents of values?

int[] values = {5, 6, 7, 8};
for (int index = 0; index < values.length; index++) {
values[index] = values[index] + 2 * index;
}

What value does total have when this code finishes?

int[] values = {3, 5, 7, 9, 11};
int index = 0;
int total = 0;
while (index < values.length) {
total += values[index];
index += 2;
}

What is the contents of values after this code executes?

int[] values = {1, 2, 3, 4};
for (int index = 0; index < values.length; index += 2) {
int temporary = values[index];
values[index] = values[index + 1];
values[index + 1] = temporary;
}

Select all statements that are true about this code.

int[] values = {3, 2, 4};
for (int index = 0; index < values.length; index++) {
if (index > 0) {
values[index] = values[index] + values[index - 1];
}
}

What integer does this method return? Enter the sum as a decimal number.

public static int total(int[] values) {
int result = 0;
for (int index = 0; index < values.length; index++) {
result += values[index];
}
return result;
}

For values = {6, 8, 10, 6}, enter the exact integer result.

What integer does this method return? Enter the exact product as a decimal number.

public static int multiply(int[] values) {
int result = 1;
for (int value : values) {
result *= value;
}
return result;
}

For values = {2, 3, 1, 8}, enter the exact integer result.

After this code executes, what integer is stored at values[3]? Enter the final element as an integer.

int[] values = {2, 4, 6, 5};
for (int index = 0; index < values.length; index++) {
values[index] = values[index] + 4 * index;
}