csc 120 chapter 4 quiz
The increment operator is:
++
How many times will the following for loop be executed? 10 21
12
What will be the value of x after the following code is executed? 10 20 <
200
Which of the following will open a file named MyFile.txt and allow you to read data from it?
File file = new File("MyFile.txt"); Scanner inputFile = new Scanner(file);
You can use this method to determine whether a file exists.
The File class's exists method
In all but rare cases, loops must contain within themselves:
a way to terminate
This is an item that separates other items.
delimiter
In a for statement, the control variable can only be incremented.
false
The do- while loop is a pre-test loop.
false
________ is the process of inspecting data given to the program by the user and determining if it is valid.
input validation
A sentinel value ________ and signals that there are no more values to be entered.
is a special value that cannot be mistaken as a member of the list
In the following code, what values could be read into number to terminate the while loop?
the boolean condition can never be true
A file must always be opened before using it and closed when the program is finished using it.
true
When you open a file with the PrintWriter class, the class can potentially throw an IOException.
true
How many times will the following do-while loop be executed?
1
This type of loop is ideal in situations where the exact number of iterations is known.
for loop
When using the PrintWriter class, which of the following import statements would you write near the top of your program?
import java.io.*;
Assume that inputFile references a Scanner object that was used to open a file. Which of the following while loops shows the correct way to read data from the file until the end of the file is reached?
while (inputFile.hasNext()) { ... }
Each repetition of a loop is known as what?
an iteration
What will be the value of x after the following code is executed? int x, y = 15, z = 3; x = (y--) / (++z);
3
When the break statement is encountered in a loop, all the statements in the body of the loop that appear after it are ignored, and the loop prepares for the next iteration.
false
If a loop does not contain within itself a way to terminate, it is called a(n):
infinite loop
What will be the value of x after the following code is executed? >
infinite loop
This variable controls the number of times that the loop iterates.
loop control variable
This is a sum of numbers that accumulates with each iteration of a loop.
running total
When the continue statement is encountered in a loop, all the statements in the body of the loop that appear after it are ignored, and the loop prepares for the next iteration.
true
You can use the PrintWriter class to open a file for writing and write data to it.
true
What will be the values of x and y as a result of the following code? int x = 12, y = 5; x += y--;
x = 17, y = 4
What will be the values of x and y as a result of the following code? int x = 25, y = 8; x += y++;
x = 33, y = 9
A loop that executes as long as a particular condition exists is called a(n):
conditional loop
A loop that repeats a specific number of times is known as a(n):
counter-controlled loop