Java Reference
In-Depth Information
switch statement is acceptable in an output method. The month input can be
handled in any manner you wish so long as it is relatively easy and pleasant for the
user. Include a loop that allows the user to repeat this entire calculation until the
user requests that the program end.
4. Write a static method called deleteRepeats that has a partially filled array of
characters as a formal parameter and that deletes all repeated letters from the array.
Because a partially filled array requires two arguments, the method should actually
have two formal parameters: an array parameter and a formal parameter of type int
that gives the number of array positions used. When a letter is deleted, the remain-
ing letters are moved one position to fill in the gap. This creates empty positions at
the end of the array so that less of the array is used. Because the formal parameter
is a partially filled array, a second formal parameter of type int should tell how
many array positions are filled. This second formal parameter cannot be changed
by a Java method, so have the method return the new value for this parameter. For
example, consider the following code:
char a[10];
a[0] = 'a';
a[1] = 'b';
a[2] = 'a';
a[3] = 'c';
int size = 4;
size = deleteRepeats(a, size);
After this code is executed, the value of a[0] is 'a' , the value of a[1] is 'b' , the
value of a[2] is 'c' , and the value of size is 3 . (The value of a[3] is no longer of
any concern, because the partially filled array no longer uses this indexed variable.)
You may assume that the partially filled array contains only lowercase letters. Write
a suitable test program for your method.
5. The standard deviation of a list of numbers is a measure of how much the numbers
deviate from the average. If the standard deviation is small, the numbers are clus-
tered close to the average. If the standard deviation is large, the numbers are scat-
tered far from the average. The standard deviation of a list of numbers n 1 , n 2 , n 3 ,
and so forth is defined as the square root of the average of the following numbers:
(n 1 - a) 2 , (n 2 - a) 2 , (n 3 - a) 2 , and so forth.
The number a is the average of the numbers n 1 , n 2 , n 3 , and so forth.
Define a static method that takes a partially filled array of numbers as its argument
and returns the standard deviation of the numbers in the partially filled array.
Because a partially filled array requires two arguments, the method should actually
have two formal parameters, an array parameter and a formal parameter of type int
that gives the number of array positions used. The numbers in the array should be
of type double . Write a suitable test program for your method.
Search WWH ::




Custom Search