Skip to main content

insert a character before and after evrey letter in a string



i want to insert a % character before after every letter in a string , but using StringBuilder to make it fast.





for example,





if a string is 'AA'







then it would be '%A%A%'







if it is 'XYZ'







then it would be '%X%Y%Z%'




Comments

  1. String foo = "VWXYZ";
    foo = "%" + foo.replaceAll("(.)","$1%");
    System.out.println(foo);


    Output:


    %V%W%X%Y%Z%


    You don't need a StringBuilder. The compiler will take care of that simple concatenation prior to the regex for you by using one.

    Edit in response to comment below:

    replaceAll() uses a Regular Expression (regex).

    The regex (.) says "match any character, and give me a reference to it" . is a wildcard for any character, the parenthesis create the backreference. The $1 in the second argument says "Use backreference #1 from the match".

    replaceAll() keeps running this expression over the whole string replacing each character with itself followed by a percent sign, building a new String which it then returns to you.

    ReplyDelete
  2. string str="AA";
    StringBuilder sb = new StringBuilder();
    for(int i = 0; i < str.length(); s++)
    {
    sb.append("%");
    sb.append(str.charAt(i));
    }
    sb.append("%");


    This is the simpliest way to do that.

    ReplyDelete
  3. Try something like this:

    String test = "ABC";
    StringBuilder builder = new StringBuilder("");
    builder.append("%");
    for (char achar : test.toCharArray()) {
    builder.append(achar);
    builder.append("%");
    }
    System.out.println(builder.toString());

    ReplyDelete
  4. public static String escape(String s) {
    StringBuilder buf = new StringBuilder();
    boolean wasLetter = false;
    for (char c: s.toCharArray()) {
    boolean isLetter = Character.isLetter(c);
    if (isLetter && !wasLetter) {
    buf.append('%');
    }
    buf.append(c);
    if (isLetter) {
    buf.append('%');
    }
    wasLetter = isLetter;
    }
    return buf.toString();
    }

    ReplyDelete
  5. StringBuilder sb = new StringBuilder("AAAAAAA");

    for(int i = sb.length(); i >= 0; i--)
    {
    sb.insert(i, '%');
    }

    ReplyDelete
  6. You may see this.

    String s="AAAA";
    StringBuilder builder = new StringBuilder();
    char[] ch=s.toCharArray();
    for(int i=0;i<ch.length;i++)
    {
    builder.append("%"+ch[i]);
    }
    builder.append("%");
    System.out.println(builder.toString());


    Output

    %A%A%A%A%

    ReplyDelete

Post a Comment

Popular posts from this blog

Why is this Javascript much *slower* than its jQuery equivalent?

I have a HTML list of about 500 items and a "filter" box above it. I started by using jQuery to filter the list when I typed a letter (timing code added later): $('#filter').keyup( function() { var jqStart = (new Date).getTime(); var search = $(this).val().toLowerCase(); var $list = $('ul.ablist > li'); $list.each( function() { if ( $(this).text().toLowerCase().indexOf(search) === -1 ) $(this).hide(); else $(this).show(); } ); console.log('Time: ' + ((new Date).getTime() - jqStart)); } ); However, there was a couple of seconds delay after typing each letter (particularly the first letter). So I thought it may be slightly quicker if I used plain Javascript (I read recently that jQuery's each function is particularly slow). Here's my JS equivalent: document.getElementById('filter').addEventListener( 'keyup', function () { var jsStart = (new Date).getTime()...

Is it possible to have IF statement in an Echo statement in PHP

Thanks in advance. I did look at the other questions/answers that were similar and didn't find exactly what I was looking for. I'm trying to do this, am I on the right path? echo " <div id='tabs-".$match."'> <textarea id='".$match."' name='".$match."'>". if ($COLUMN_NAME === $match) { echo $FIELD_WITH_COLUMN_NAME; } else { } ."</textarea> <script type='text/javascript'> CKEDITOR.replace( '".$match."' ); </script> </div>"; I am getting the following error message in the browser: Parse error: syntax error, unexpected T_IF Please let me know if this is the right way to go about nesting an IF statement inside an echo. Thank you.