test2

Class Utility2B

java.lang.Object

test2.Utility2B

public class Utility2B
extends Object

Method Summary

Modifier and Type	Method and Description
static int	distance(String s, String t) Computes the number of characters that are different in two strings of equal length.
static boolean	isPalindrome(String s) Returns true if a string is a palindrome.
static String	join(String s, String t, String sep) Returns the string formed by concatenating the argument strings s and t with a separator string between them.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

join

public static String join(String s,
                          String t,
                          String sep)

Returns the string formed by concatenating the argument strings s and t with a separator string between them. For example:

 Utility2B.join("abc", "xyz", ":")
 

returns the string "abc:xyz".

Parameters:

s - a non-null string

t - a non-null string

sep - a non-null separator string

Returns:

the string formed by concatenating s followed by sep followed by t

distance

public static int distance(String s,
                           String t)

Computes the number of characters that are different in two strings of equal length. The strings are compared character by character and the number of characters that differ is returned. For example:

 Utility2B.distance("talk", "talk")    returns  0
 Utility2B.distance("talk", "walk")    returns  1
 Utility2B.distance("well", "walk")    returns  2    
 Utility2B.distance("pick", "walk")    returns  3
 Utility2B.distance("zzzz", "walk")    returns  4
 

Parameters:

s - a non-null string

t - a non-null string

Returns:

the number of characters that differ between s and t

Throws:

IllegalArgumentException - if s and t have different lengths

isPalindrome

public static boolean isPalindrome(String s)

Returns true if a string is a palindrome. A string is a palindrome if it contains the same sequence of characters when read forwards or backwards. For example, the following strings are all palindromes:

 "noon"
 "level"
 "racecar"
 

The empty string is considered to be a palindrome.

Parameters:

s - a non-null string

Returns:

true if s is a palindrome and false otherwise