Strings (Starlink-UK API)

java.lang.Object
- uk.ac.starlink.ttools.func.Strings

```
public class Strings
extends Object
```
String manipulation and query functions.

Since:

2 Sep 2004

Author:

Mark Taylor (Starlink)

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static String`	`concat(Object... strings)` Concatenates multiple values into a string.
`static boolean`	`contains(String whole, String sub)` Determines whether a string contains a given substring.
`static double`	`desigToDec(String designation)` Attempts to determine the ICRS Declination from an IAU-style designation such as "`2MASS J04355524+1630331`" following the specifications in the document https://cdsweb.u-strasbg.fr/Dic/iau-spec.html.
`static double[]`	`desigToIcrs(String designation)` Attempts to decode an IAU-style designation such as "`2MASS J04355524+1630331`" to determine its sky position, following the specifications in the document https://cdsweb.u-strasbg.fr/Dic/iau-spec.html.
`static double`	`desigToRa(String designation)` Attempts to determine the ICRS Right Ascension from an IAU-style designation such as "`2MASS J04355524+1630331`" following the specifications in the document https://cdsweb.u-strasbg.fr/Dic/iau-spec.html.
`static boolean`	`endsWith(String whole, String end)` Determines whether a string ends with a certain substring.
`static boolean`	`equals(String s1, String s2)` Determines whether two strings are equal.
`static boolean`	`equalsIgnoreCase(String s1, String s2)` Determines whether two strings are equal apart from possible upper/lower case distinctions.
`static String`	`join(String separator, Object... words)` Joins multiple values into a string, with a given separator between each pair.
`static int`	`length(String str)` Returns the length of a string in characters.
`static boolean`	`matches(String str, String regex)` Tests whether a string matches a given regular expression.
`static String`	`matchGroup(String str, String regex)` Returns the first grouped expression matched in a string defined by a regular expression.
`static 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.
`static String`	`replaceAll(String str, String regex, String replacement)` Replaces all occurrences of a regular expression in a string with a different substring value.
`static String`	`replaceFirst(String str, String regex, String replacement)` Replaces the first occurrence of a regular expression in a string with a different substring value.
`static String[]`	`split(String words)` Splits a string into an array of space-separated words.
`static String[]`	`split(String words, String regex)` Splits a string into an array of words separated by a given regular expression.
`static boolean`	`startsWith(String whole, String start)` Determines whether a string starts with a certain substring.
`static String`	`substring(String str, int startIndex)` Returns the last part of a given string.
`static String`	`substring(String str, int startIndex, int endIndex)` Returns a substring of a given string.
`static String`	`toLowerCase(String str)` Returns an lowercased version of a string.
`static String`	`toUpperCase(String str)` Returns an uppercased version of a string.
`static String`	`trim(String str)` Trims whitespace from both ends of a string.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - concat
```
public static String concat(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
  - join
```
public static String join(String separator,
                          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
  - equals
```
public static boolean equals(String s1,
                             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(String s1,
                                       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
  - startsWith
```
public static boolean startsWith(String whole,
                                 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
  - endsWith
```
public static boolean endsWith(String whole,
                               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
  - contains
```
public static boolean contains(String whole,
                               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
  - length
```
public static int length(String str)
```
    Returns the length of a string in characters.
    
    Parameters:
    
    str - string
    
    Returns:
    
    number of characters in str
  - split
```
public static String[] split(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
  - split
```
public static String[] split(String words,
                             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
  - matches
```
public static boolean matches(String str,
                              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
  - matchGroup
```
public static String matchGroup(String str,
                                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)
  - replaceFirst
```
public static String replaceFirst(String str,
                                  String regex,
                                  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
  - replaceAll
```
public static String replaceAll(String str,
                                String regex,
                                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
  - substring
```
public static String substring(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
  - substring
```
public static String substring(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
  - toUpperCase
```
public static String toUpperCase(String str)
```
    Returns an uppercased version of a string.
    
    Parameters:
    
    str - input string
    
    Returns:
    
    uppercased version of str
  - toLowerCase
```
public static String toLowerCase(String str)
```
    Returns an lowercased version of a string.
    
    Parameters:
    
    str - input string
    
    Returns:
    
    lowercased version of str
  - trim
```
public static String trim(String str)
```
    Trims whitespace from both ends of a string.
    
    Parameters:
    
    str - input string
    
    Returns:
    
    str with any spaces trimmed from start and finish
  - padWithZeros
```
public static 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
  - desigToRa
```
public static double desigToRa(String designation)
```
    Attempts to determine the ICRS Right Ascension from an IAU-style designation such as "2MASS J04355524+1630331" following the specifications in the document https://cdsweb.u-strasbg.fr/Dic/iau-spec.html.
    Note: this function should be used with considerable care. Such designators are intended for object identification and not for communicating sky positions, so that the resulting positions are likely to lack precision, and may be inaccurate. If positional information is available from other sources, it should almost certainly be used instead. But if there's no other choice, this may be used as a fallback.
    Note also that a designator with no coordsystem-specific flag character (a leading "J", "B" or "G") is considered to be B1950, not J2000.
    
    Parameters:
    
    designation - designation string in IAU format
    
    Returns:
    
    ICRS right ascension in degreees, or blank if no position can be decoded
  - desigToDec
```
public static double desigToDec(String designation)
```
    Attempts to determine the ICRS Declination from an IAU-style designation such as "2MASS J04355524+1630331" following the specifications in the document https://cdsweb.u-strasbg.fr/Dic/iau-spec.html.
    Note: this function should be used with considerable care. Such designators are intended for object identification and not for communicating sky positions, so that the resulting positions are likely to lack precision, and may be inaccurate. If positional information is available from other sources, it should almost certainly be used instead. But if there's no other choice, this may be used as a fallback.
    Note also that a designator with no coordsystem-specific flag character (a leading "J", "B" or "G") is considered to be B1950, not J2000.
    
    Parameters:
    
    designation - designation string in IAU format
    
    Returns:
    
    ICRS declination in degrees, or blank if no position can be decoded
  - desigToIcrs
```
public static double[] desigToIcrs(String designation)
```
    Attempts to decode an IAU-style designation such as "2MASS J04355524+1630331" to determine its sky position, following the specifications in the document https://cdsweb.u-strasbg.fr/Dic/iau-spec.html.
    Obviously, this only works where the sequence part of the designation takes one of the family of coordinate-based forms.
    Note: this function should be used with considerable care. Such designators are intended for object identification and not for communicating sky positions, so that the resulting positions are likely to lack precision, and may be inaccurate. If positional information is available from other sources, it should almost certainly be used instead. But if there's no other choice, this may be used as a fallback.
    Note also that a designator with no coordsystem-specific flag character (a leading "J", "B" or "G") is considered to be B1950, not J2000.
    
    Parameters:
    
    designation - designation string in IAU format
    
    Returns:
    
    2-element array giving ICRS (RA,Dec) in degrees, or null if no position can be decoded

Class Strings

Method Summary

Methods inherited from class java.lang.Object

Method Detail

concat

join

equals

equalsIgnoreCase

startsWith

endsWith

contains

length

split

split

matches

matchGroup

replaceFirst

replaceAll

substring

substring

toUpperCase

toLowerCase

trim

padWithZeros

desigToRa

desigToDec

desigToIcrs