How to remove newlines from beginning and end of a string

Question

I have a string that contains some text followed by a blank line  What s the best way to keep the part with text  but remove the whitespace newline from the end

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String text   readFileAsString  textfile txt    text   text replace   n       replace   r

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If your string is potentially null  consider using StringUtils trim   - the null-safe version of String trim

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String replaceAll    n r

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Another elegant solution  String myString    quot  nLogbasex n quot   myString   org apache commons lang3 StringUtils strip myString   quot  n quot

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Use String trim   method to get rid of whitespaces  spaces  new lines etc   from the beginning and end of the string   String trimmedString   myString trim

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Try this function replaceNewLine str       return str replace    n r  g   quot  quot

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tl dr  String cleanString   dirtyString strip        Call new  String  string  method    String  strip     The old String  trim method has a strange definition of whitespace   As discussed here  Java 11 adds new strip    methods to the String class  These use a more Unicode-savvy definition of whitespace  See the rules of this definition in the class JavaDoc for Character  isWhitespace   Example code   String input     some Thing    System out println  before- gt  gt   input   lt  lt -    input   input strip    System out println  after- gt  gt   input   lt  lt -      Or you can strip just the leading or just the trailing whitespace   You do not mention exactly what code point s  make up your newlines  I imagine your newline is likely included in this list of code points targeted by strip    It is a Unicode space character  SPACE SEPARATOR  LINE SEPARATOR  or PARAGRAPH SEPARATOR  but is not also a non-breaking space    u00A0     u2007     u202F    It is   t   U 0009 HORIZONTAL TABULATION  It is   n   U 000A LINE FEED  It is   u000B   U 000B VERTICAL TABULATION  It is   f   U 000C FORM FEED  It is   r   U 000D CARRIAGE RETURN  It is   u001C   U 001C FILE SEPARATOR  It is   u001D   U 001D GROUP SEPARATOR  It is   u001E   U 001E RECORD SEPARATOR  It is   u001F   U 0

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If you only want to remove line breaks  not spaces  tabs  at the beginning and end of a String  not inbetween   then you can use this approach  Use a regular expressions to remove carriage returns    r  and line feeds    n  from the beginning     and ending     of a string   s   s replaceAll  quot      r  n      r  n     quot    quot  quot    Complete Example  public class RemoveLineBreaks       public static void main String   args            var s    quot  nHello nWorld n quot           System out println  quot before   gt  quot  s  quot  lt  quot            s   s replaceAll  quot      r  n      r  n     quot    quot  quot            System out println  quot after   gt  quot  s  quot  lt  quot             It outputs  before   gt  Hello World  lt  after   gt Hello World lt

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I m going to add an answer to this as well because  while I had the same question  the provided answer did not suffice  Given some thought  I realized that this can be done very easily with a regular expression   To remove newlines from the beginning      Trim left String   a     n nfrom the beginning n n  split     n    2    System out println  -     a length  gt  1   a 1    a 0      -      and end of a string      Trim right String z     n nfrom the end n n    System out println  -    z split    n     2  0     -      I m certain that this is not the most performance efficient way of trimming a string  But it does appear to be the cleanest and simplest way to inline such an operation   Note that the same method can be done to trim any variation and combination of characters from either end as it s a simple regex

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For anyone else looking for answer to the question when dealing with different linebreaks  string replaceAll  quot   n  r  r n   quot    quot  quot       Java 7 string replaceAll  quot   R  quot    quot  quot                Java 8  This should remove exactly the last line break and preserve all other whitespace from string and work with Unix   n   Windows   r n  and old Mac   r  line breaks  https   stackoverflow com a 20056634  https   stackoverflow com a 49791415   quot   R quot  is matcher introduced in Java 8 in Pattern class  https   docs oracle com javase 8 docs api java util regex Pattern html This passes these tests     Windows  value    quot  r n test  r n value  r n quot   assertEquals  quot  r n test  r n value  quot   value replaceAll  quot   R  quot    quot  quot         Unix  value    quot  n test  n value  n quot   assertEquals  quot  n test  n value  quot   value replaceAll  quot   R  quot    quot  quot         Old Mac  value    quot  r test  r value  r quot   assertEquals  quot  r test  r value  quot   value replaceAll  quot   R  quot    quot  quot

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String trimStartEnd     n TestString1 linebreak1 nlinebreak2 nlinebreak3 n TestString2  n   System out println  Original String        trimStartEnd         System out println  -----------------------------    System out println  Result String        trimStartEnd replaceAll      r  n    n  x0B  x0C  r  u0085  u2028  u2029      r  n    n  x0B  x0C  r  u0085  u2028  u2029                     Start of a string       End of a string       regex combination       Linebreak    r n   n x0B x0C r u0085 u2028 u2029

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This Java code does exactly what is asked in the title of the question  that is  remove newlines from beginning and end of a string-java    String replaceAll     n r        replaceAll    n r           Remove newlines only from the end of the line   String replaceAll    n r           Remove newlines only from the beginning of the line   String replaceAll     n r

[java] How to remove newlines from beginning and end of a string?

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