Starting Out with Java From Control Structures through Data Structures Test #2 - Chapter 4
for loop
A type of loop is ideal in situations where the exact number of iterations is unknown
Post-test loop
A type of loop will always be executed at least once
Sentinel
A value that signals when the end of a list values has been reached
Open a file names MyFile.txt and allows you to append data to its existing contents
FileWriter fwriter = new FileWriter("MyFile.txt", true); PrintWriter outFile = new PrintWriter(fwriter);
PrintWriter outputFile = new PrintWriter("StudentData.txt);
StudentData.txt is the file name
PrintWriter class
a class allows you to open a file for writing
user controlled loop
a loop asks the user whether he or she wants to repeat the process
An infinite loop
a loop does not contain within itself a way to terminate
infinite loop
a loop does not have a way of stopping
nested loop
a loop that is inside another loop
count-controlled loop
a loop that repeats a specific number of times
exception
a signal indicating that the program cannot continue until the unexpected event has been dealt with
continue
a statement causes a loop to stop its current iteration and begin the next one
break
a statement causes a loop to terminate early
counter variable
a variable keeps a count of the number of iterations
while, for
are pre-test loops
text file
contains data that has been encoded as text, using a scheme such as Unicode
number-- and --number
decrements the variable number
conditional loop
executes as long as a particular condition exists
import java.io.*;
file input and output
while loop
has two parts. (1) a boolean expression that is tested for a true or false value, and (2) a statement or block of statements that is repeated as long as the expression is true.
number++ and ++number
increments the variable number
loop
is a control structure that causes a statement or group of statements to repeat
input file
is a file that a program reads data from
output file
is a file that a program writes data to
do-while loop
is a posttest loop, which it does not test its boolean expression until it has completed an iteration
buffer
is a small "holding section" of memory
Sentinel Value
is a special value that cannot be mistaken as a member of the list and signals that there are no more values t be entered
running total
is a sum of numbers that accumulates with each iteration of a loop
delimiter
is an item that separates others items
input validation
is the process of inspecting data given clear instructions about kind of input that is acceptable, and not assume the user has followed those instructions
print method
is used to write an item of data to file without writing the newline character
number--
number minus minus
number++
number plus plus
number
the control variable in this loop
initialization expression
the first expression
loop header
the first line of the for loop
postfit mode
the operator is placed after the variable
prefit mode
the operator is placed before the variable
priming read
the read operation that takes place just before the loop
test expression
the second expression
update expression
the third expression
accumulator
the variable used to accumulate the total of the numbers
pretest loop
the while loop, which means it tests it's expressions before each iteration
FileWriter fwriter = new FileWriter("MyFriends.txt", true)
this statement causes a FileWriter object and opens the file MyFriends.txt for writing,
Assume that inputFile references a Scanner abject that was used to open a file.
while (inputFile.hasNext()); {.....}
