Method Detail

• concat

  public static java.lang.String concat(java.lang.Object... strings)

  Concatenates multiple values into a string. In some cases the same effect can be achieved by writing s1+s2+..., but this method makes sure that values are converted to strings, with the blank value invisible.

  Parameters:

  strings - one or more strings

  Returns:

  concatenation of input strings, without separators

  Examples:

  concat("blue", "moon") = "bluemoon", concat("1", 2, 3, "4") = "1234", concat("Astro", null, "Physics") = "AstroPhysics"

• join

  public static java.lang.String join(java.lang.String separator,
                                      java.lang.Object... words)

  Joins multiple values into a string, with a given separator between each pair.

  Parameters:

  separator - string to insert between adjacent words

  words - one or more values to join

  Returns:

  input values joined together with separator

  Examples:

  join("<->", "alpha", "beta", "gamma") = "alpha<->beta<->gamma", join(" ", 1, "brown", "mouse") = "1 brown mouse"

• equals

  public static boolean equals(java.lang.String s1,
                               java.lang.String s2)

  Determines whether two strings are equal. Note you should use this function instead of s1==s2, which can (for technical reasons) return false even if the strings are the same.

  Parameters:

  s1 - first string

  s2 - second string

  Returns:

  true if s1 and s2 are both blank, or have the same content

• equalsIgnoreCase

  public static boolean equalsIgnoreCase(java.lang.String s1,
                                         java.lang.String s2)

  Determines whether two strings are equal apart from possible upper/lower case distinctions.

  Parameters:

  s1 - first string

  s2 - second string

  Returns:

  true if s1 and s2 are both blank, or have the same content apart from case folding

  Examples:

  equalsIgnoreCase("Cygnus", "CYGNUS") = true, equalsIgnoreCase("Cygnus", "Andromeda") = false

• startsWith

  public static boolean startsWith(java.lang.String whole,
                                   java.lang.String start)

  Determines whether a string starts with a certain substring.

  Parameters:

  whole - the string to test

  start - the sequence that may appear at the start of whole

  Returns:

  true if the first few characters of whole are the same as start

  Examples:

  startsWith("CYGNUS X-1", "CYG") = true

• endsWith

  public static boolean endsWith(java.lang.String whole,
                                 java.lang.String end)

  Determines whether a string ends with a certain substring.

  Parameters:

  whole - the string to test

  end - the sequence that may appear at the end of whole

  Returns:

  true if the last few characters of whole are the same as end

  Examples:

  endsWith("M32", "32") = true

• contains

  public static boolean contains(java.lang.String whole,
                                 java.lang.String sub)

  Determines whether a string contains a given substring.

  Parameters:

  whole - the string to test

  sub - the sequence that may appear within whole

  Returns:

  true if the sequence sub appears within whole

  Examples:

  contains("Vizier", "izi") = true

• length

  public static int length(java.lang.String str)

  Returns the length of a string in characters.

  Parameters:

  str - string

  Returns:

  number of characters in str

  Examples:

  length("M34") = 3

• split

  public static java.lang.String[] split(java.lang.String words)

  Splits a string into an array of space-separated words. One or more spaces separates each word from the next. Leading and trailing spaces are ignored.

  The result is an array of strings, and if you want to use the individual elements you need to use square-bracket indexing, with [0] representing the first object

  Parameters:

  words - string with embedded spaces delimiting the words

  Returns:

  array of the separate words; you can extract the individual words from the result using square bracket indexing

  Examples:

  split("211:54:01 +29:33:41") gives a 2-element array, first element is "211:54:01" and second element is "+29:33:41"., split(" cat dog cow ")[1] = "dog"

• split

  public static java.lang.String[] split(java.lang.String words,
                                         java.lang.String regex)

  Splits a string into an array of words separated by a given regular expression.

  The result is an array of strings, and if you want to use the individual elements you need to use square-bracket indexing, with [0] representing the first object

  Parameters:

  words - string with multiple parts

  regex - regular expression delimiting the different words in the words parameter

  Returns:

  array of the separate words; you can extract the individual words from the result using square bracket indexing

  Examples:

  split("cat, dog, cow", ", *") gives a 3-element string array., split("23.0, 45.92", ", ")[0] = "23.0", parseDouble(split("23.0, 45.92", ", ")[0]) = 23

• matches

  public static boolean matches(java.lang.String str,
                                java.lang.String regex)

  Tests whether a string matches a given regular expression.

  Parameters:

  str - string to test

  regex - regular expression string

  Returns:

  true if regex matches str anywhere

  Examples:

  matches("Hubble", "ub") = true

• matchGroup

  public static java.lang.String matchGroup(java.lang.String str,
                                            java.lang.String regex)

  Returns the first grouped expression matched in a string defined by a regular expression. A grouped expression is one enclosed in parentheses.

  Parameters:

  str - string to match against

  regex - regular expression containing a grouped section

  Returns:

  contents of the matched group (or null, if regex didn't match str)

  Examples:

  matchGroup("NGC28948b","NGC([0-9]*)") = "28948"

• replaceFirst

  public static java.lang.String replaceFirst(java.lang.String str,
                                              java.lang.String regex,
                                              java.lang.String replacement)

  Replaces the first occurrence of a regular expression in a string with a different substring value.

  Parameters:

  str - string to manipulate

  regex - regular expression to match in str

  replacement - replacement string

  Returns:

  same as str, but with the first match (if any) of regex replaced by replacement

  Examples:

  replaceFirst("Messier 61", "Messier ", "M-") = "M-61"

• replaceAll

  public static java.lang.String replaceAll(java.lang.String str,
                                            java.lang.String regex,
                                            java.lang.String replacement)

  Replaces all occurrences of a regular expression in a string with a different substring value.

  Parameters:

  str - string to manipulate

  regex - regular expression to match in str

  replacement - replacement string

  Returns:

  same as str, but with all matches of regex replaced by replacement

  Examples:

  replaceAll("1-2--3---4","--*","x") = "1x2x3x4"

• substring

  public static java.lang.String substring(java.lang.String str,
                                           int startIndex)

  Returns the last part of a given string. The substring begins with the character at the specified index and extends to the end of this string.

  Parameters:

  str - the input string

  startIndex - the beginning index, inclusive

  Returns:

  last part of str, omitting the first startIndex characters

  Examples:

  substring("Galaxy", 2) = "laxy"

• substring

  public static java.lang.String substring(java.lang.String str,
                                           int startIndex,
                                           int endIndex)

  Returns a substring of a given string. The substring begins with the character at startIndex and continues to the character at index endIndex-1 Thus the length of the substring is endIndex-startIndex.

  Parameters:

  str - the input string

  startIndex - the beginning index, inclusive

  endIndex - the end index, inclusive

  Returns:

  substring of str

  Examples:

  substring("Galaxy", 2, 5) = "lax"

• toUpperCase

  public static java.lang.String toUpperCase(java.lang.String str)

  Returns an uppercased version of a string.

  Parameters:

  str - input string

  Returns:

  uppercased version of str

  Examples:

  toUpperCase("Universe") = "UNIVERSE"

• toLowerCase

  public static java.lang.String toLowerCase(java.lang.String str)

  Returns an lowercased version of a string.

  Parameters:

  str - input string

  Returns:

  lowercased version of str

  Examples:

  toLowerCase("Universe") = "universe"

• trim

  public static java.lang.String trim(java.lang.String str)

  Trims whitespace from both ends of a string.

  Parameters:

  str - input string

  Returns:

  str with any spaces trimmed from start and finish

  Examples:

  trim(" some text ") = "some text", trim("some text") = "some text"

• padWithZeros

  public static java.lang.String padWithZeros(long value,
                                              int ndigit)

  Takes an integer argument and returns a string representing the same numeric value but padded with leading zeros to a specified length.

  Parameters:

  value - numeric value to pad

  ndigit - the number of digits in the resulting string

  Returns:

  a string evaluating to the same as value with at least ndigit characters

  Examples:

  padWithZeros(23,5) = "00023"