Get string character by index - Java

Question

I know how to work out the index of a certain character or number in a string  but is there any predefined method I can use to give me the character at the nth position  So in the string  foo   if I asked for the character with index 0 it would return  f    Note - in the above question  by  character  I don t mean the char data type  but a letter or number in a string  The important thing here is that I don t receive a char when the method is invoked  but a string  of length 1   And I know about the substring   method  but I was wondering if there was a neater way

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Here s the correct code  If you re using zybooks this will answer all the problems   for  int i   0  i lt passCode length    i          char letter   passCode charAt i       if  letter                        System out println  Space at     i

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None of the proposed answers works for surrogate pairs used to encode characters outside of the Unicode Basic Multiligual Plane   Here is an example using three different techniques to iterate over the  characters  of a string  incl  using Java 8 stream API   Please notice this example includes characters of the Unicode Supplementary Multilingual Plane  SMP   You need a proper font to display this example and the result correctly      String containing characters of the Unicode     Supplementary Multilingual Plane  SMP     In that particular case  hieroglyphs  String str    The quick brown  jumps over the lazy      Iterate of chars  The first solution is a simple loop over all char of the string      1    System out println            n nUsing char iterator  do not work for surrogate pairs       for  int pos   0  pos  lt  str length      pos        char c   str charAt pos       System out printf   s    Character toString c                                                                                Convert to String as per OP request     Iterate of code points  The second solution uses an explicit loop too  but accessing individual  code points with codePointAt and incrementing the loop index accordingly to charCount      2    System out println            n nUsing Java 1 5 codePointAt works as expected     for  int pos   0  pos  lt  str length           int cp   str codePointAt pos        char    chars     Character toChars cp                                                                    Convert to a  char                         as code points outside the Unicode BMP                      will map to more than one Java  char      System out printf   s    new String chars                                                                        Convert to String as per OP request      pos    Character charCount cp                                                Increment pos by 1 of more depending           the number of Java  char  required to           encode that particular codepoint      Iterate over code points using the Stream API  The third solution is basically the same as the second  but using the Java 8 Stream API      3    System out println            n nUsing Java 8 stream  works as expected     str codePoints   forEach      cp - gt            char    chars     Character toChars cp                                                                            Convert to a  char                             as code points outside the Unicode BMP                          will map to more than one Java  char          System out printf   s    new String chars                                                                                Convert to String as per OP request           Results  When you run that test program  you obtain   Using char iterator  do not work for surrogate pairs    T h e   q u i c k   b r o w n         j u m p s   o v e r   t h e   l a z y                     Using Java 1 5 codePointAt works as expected  T h e   q u i c k   b r o w n      j u m p s   o v e r   t h e   l a z y         Using Java 8 stream  works as expected  T h e   q u i c k   b r o w n      j u m p s   o v e r   t h e   l a z y          As you can see  if you re able to display hieroglyphs properly   the first solution does not handle properly characters outside of the Unicode BMP  On the other hand  the other two solutions deal well with surrogate pairs

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You want  charAt    Here s a tutorial   mystring  charAt 2    returns s  If you re hellbent on having a string there are a couple of ways to convert a char to a string   String mychar   Character toString  mystring  charAt 2      Or   String mychar       mystring  charAt 2     Or even  String mychar   String valueOf  mystring  charAt 2      For example

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A hybrid approach combining charAt with your requirement of not getting  char could be  newstring   String valueOf  foo  charAt 0      But that s not really  neater  than substring   to be honest

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Like this   String a   hh1hhhhhhhh   char s   a charAt 3

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CharAt function not working Edittext setText YourString toCharArray   0 1   This code working fine

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CodePointAt instead of charAt is safer to use  charAt may break when there are emojis in the strtng

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if someone is strugling with kotlin  the code is   var oldStr  String    kotlin  var firstChar  String   oldStr elementAt 0  toString   Log d  firstChar   firstChar toString      this will return the char in position 1  in this case k remember  the index starts in position 0  so in this sample  kotlin would be k position 0  o position 1  t position 2  l position 3  i position 4 and n position 5

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You could use the String charAt int index  method result as the parameter for String valueOf char c     String valueOf myString charAt 3      This will return a string of the character on the 3rd position

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It is as simple as   String charIs   string charAt index

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You re pretty stuck with substring    given your requirements   The standard way would be charAt    but you said you won t accept a char data type

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The method you re looking for is charAt  Here s an example   String text    foo   char charAtZero   text charAt 0   System out println charAtZero      Prints f   For more information  see the Java documentation on String charAt  If you want another simple tutorial  this one or this one   If you don t want the result as a char data type  but rather as a string  you would use the Character toString method   String text    foo   String letter   Character toString text charAt 0    System out println letter      Prints f   If you want more information on the Character class and the toString method  I pulled my info from the documentation on Character toString

[java] Get string character by index - Java

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