Posted in: darrelrussell.com edit
20 Nov 2008
Check03C (TS = 35)
We want to develop an app that converts a distance in centimeters into
the corresponding distance in miles, yards, feet and inches. Recall
that
1 mile is 1760 yards,
1 yard is 3 feet, and
1 yard is 36 inches
and that
1 centimeter is appromately 0.01094 yards.
Analysis
The input must be prompted with the message
Enter the distance in centimeters
The entry is made on the next line; it consists of a nonnegative whole
number. If the entry is not a whole number, then an exception should
occur. If the entry is negative, then a runtime exception with the
message Value out of range should occur. The output consists of one
line containing, from left to right, the following elements separated
by a space: the entered number, the string cm, the equal sign, the
corresponding number of miles, the string miles,, the corresponding
number of yards, the string yards,, the corresponding number of feet,
the string feet, and, the corresponding inches rounded to two
decimals, and the string inches. Here are some sample runs of the
proposed system:
Enter the distance in centimeters
1234567
1234567 cm = 7 miles, 1186 yards, 0 feet, and 5.87 inches
Enter the distance in centimeters
1
1 cm = 0 miles, 0 yards, 0 feet, and 0.39 inches
Enter the distance in centimeters
553
553 cm = 0 miles, 6 yards, 0 feet, and 1.79 inches
Enter the distance in centimeters
-5
Exception in thread "main" java.lang.RuntimeException: Value out of range
....
Enter the distance in centimeters
2.5
Exception in thread "main" java.util.InputMismatchException
...
Enter the distance in centimeters
a
Exception in thread "main" java.util.InputMismatchException
...
Design
The tasks in our project are the following: printing on the screen,
reading from the user, validating the input, converting, formatting
and printing. The ready-made classes Scanner, PrintStream and ToolBox
contain methods for reading input, for writing and formatting output
and for input validation. This leaves the conversion issue. We can
first convert from centimeters to yards, and subsequently determine
the number of miles, yards, feet and inches.
Implementation
We leave this part to you.
Testing
We need to test our app to establish confidence in the correctness of
our program. We supply various input cases to it, examine the output
for each, and compare it with what we deem to be the correct answer.
Here are some input cases (and the expected output):
Normal cases: 3 (little more than 1 inch), 31 (little more than 1
foot), 91 (little more than 1 yard), 161000 (little more than 1 mile);
Boundary case: 0;
Out of range: -1, -100 (runtime exception with message Value out of range);
Fractional: 7.5, -5.8 (exception);
Non-numeric: one, 3a (exception);
Develop, test and eCheck Check03C.
Recall that eCheck defines correctness relative to the specification,
not to some subjective measure of goodness. It may consider your app
incorrect even if the "important" or "noncosmetic" part of it is
correct.Dear aldaweesh,
Below is a Java program, entitled Distance.java, that implements the
specifications given above. Following that is the output resulting
from the specified input cases.
Regards,
leapinglizard
//=====begin Distance.java
import java.lang.*;
import java.util.*;
import java.io.*;
public class Distance {
public static void main(String argv) throws Exception {
PrintStream out = System.out;
BufferedReader in =
new BufferedReader(new InputStreamReader(System.in));
int cm;
while (true) { // loop breaks on empty input or exception
out.println("Enter the distance in centimeters");
String line = in.readLine();
if (line == null)
break;
try { // attempt integer conversion
cm = new Integer(line).intValue();
} catch (NumberFormatException e) {
throw new InputMismatchException();
}
if (cm < 0) // exception for negative value
throw new RuntimeException("Value out of range");
// convert to inches as per specification
double inches_double = cm * 0.01094 * 36;
int inches = (int) inches_double;
int miles = inches / (1760 * 36);
inches -= 1760 * 36 * miles;
int yards = inches / 36;
inches -= 36 * yards;
int feet = inches / 12;
inches -= 12 * feet;
// compute first two decimal digits
double decimal = inches_double - (double) ((int) inches_double);
int decimal_int = (int) Math.round(100 * decimal);
int tens = decimal_int / 10;
int ones = decimal_int % 10;
out.print(cm+" cm = "); // print results as specified
out.print(miles+" miles, ");
out.print(yards+" yards, ");
out.print(feet+" feet, and ");
out.print(inches+"."+tens+ones+" inchesnn");
}
}
}
//=====end Distance.java
$ java Distance
Enter the distance in centimeters
3
3 cm = 0 miles, 0 yards, 0 feet, and 1.18 inches
Enter the distance in centimeters
31
31 cm = 0 miles, 0 yards, 1 feet, and 0.21 inches
Enter the distance in centimeters
91
91 cm = 0 miles, 0 yards, 2 feet, and 11.84 inches
Enter the distance in centimeters
161000
161000 cm = 1 miles, 1 yards, 1 feet, and 0.24 inches
Enter the distance in centimeters
0
0 cm = 0 miles, 0 yards, 0 feet, and 0.00 inches
Enter the distance in centimeters
-1
Exception in thread "main" java.lang.RuntimeException: Value out of range
at Distance.main(Distance.java:27)
$ java Distance
Enter the distance in centimeters
-100
Exception in thread "main" java.lang.RuntimeException: Value out of range
at Distance.main(Distance.java:27)
$ java Distance
Enter the distance in centimeters
7.5
Exception in thread "main" java.util.InputMismatchException
at Distance.main(Distance.java:23)
$ java Distance
Enter the distance in centimeters
-5.8
Exception in thread "main" java.util.InputMismatchException
at Distance.main(Distance.java:23)
$ java Distance
Enter the distance in centimeters
one
Exception in thread "main" java.util.InputMismatchException
at Distance.main(Distance.java:23)
$ java Distance
Enter the distance in centimeters
3a
Exception in thread "main" java.util.InputMismatchException
at Distance.main(Distance.java:23)please don't use the while loop command .
please use Scanner instead of BufferedReader.You will find a new version below. There is no loop in this one, so it
prompts for input only once. I have also replaced the BufferedReader
instance with a Scanner.
leapinglizard
//=====begin Distance.java
import java.lang.*;
import java.util.*;
import java.io.*;
public class Distance {
public static void main(String argv) throws Exception {
PrintStream out = System.out;
Scanner in = new Scanner(System.in);
int cm;
out.println("Enter the distance in centimeters");
String line = in.nextLine();
try { // attempt integer conversion
cm = new Integer(line).intValue();
} catch (NumberFormatException e) {
throw new InputMismatchException();
}
if (cm < 0) // exception for negative value
throw new RuntimeException("Value out of range");
// convert to inches as per specification
double inches_double = cm * 0.01094 * 36;
int inches = (int) inches_double;
int miles = inches / (1760 * 36);
inches -= 1760 * 36 * miles;
int yards = inches / 36;
inches -= 36 * yards;
int feet = inches / 12;
inches -= 12 * feet;
// compute first two decimal digits
double decimal = inches_double - (double) ((int) inches_double);
int decimal_int = (int) Math.round(100 * decimal);
int tens = decimal_int / 10;
int ones = decimal_int % 10;
out.print(cm+" cm = "); // print results as specified
out.print(miles+" miles, ");
out.print(yards+" yards, ");
out.print(feet+" feet, and ");
out.print(inches+"."+tens+ones+" inchesn");
}
}
//=====end Distance.java
