Remove characters at certain position at string

Question

I want to remove certain characters at specific positions of the String. I have the positions, but I am facing problems removing the characters.

what i am doing is:

if (string.subSequence(k, k + 4).equals("\n\t\t\t")){
    string = string.subSequence(0, k) + "" + s.subSequence(k, s.length());
}

I need to remove "\n\t\t\t" from string

i do not want to replace all the occurrences, i want to replace a few of them at certain positions — Hassaan Rabbani, Dec 03 '13 at 14:53
Use `.substring(index)` to find your location. Convert String to char array. Change char to new char at that index. Convert back to String. — Tdorno, Dec 03 '13 at 14:54
http://stackoverflow.com/questions/13386107/how-to-remove-single-character-in-a-string-in-java have a look at this solution — Md. Arafat Al Mahmud, Dec 03 '13 at 14:58

score 15 · Answer 1 · answered Dec 03 '13 at 14:55

15

Use StringBuilder:

StringBuilder sb = new StringBuilder(str);

sb.delete(start, end);
sb.deleteCharAt(index);

String result = sb.toString();

answered Dec 03 '13 at 14:55

Zong

6,160
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score 1 · Answer 2 · answered May 10 '16 at 00:16

1

Use StringBuilder

String str="    ab a acd";
        StringBuilder sb = new StringBuilder(str);

        sb.delete(0,3);
        sb.deleteCharAt(0);

        String result = sb.toString();
        System.out.println(result);

answered May 10 '16 at 00:16

Meghana Randad

430
5
13

score 1 · Answer 3 · edited Aug 01 '18 at 06:13

1

public static String remove(int postion, String stringName) {
    char [] charArray = stringName.toCharArray();
    char [] resultArray = new char[charArray.length];
    int count = 0;
    for (int i=0; i< charArray.length; i++) {
        if (i != postion-1) {
            resultArray[count] = charArray[i];
            count++;
        }
    }
    return String.valueOf(resultArray);
}

edited Aug 01 '18 at 06:13

Yannick Huber

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answered Aug 01 '18 at 05:40

Machhindra Neupane

679
7
20

While this code may answer the question, providing additional context regarding how and/or why it solves the problem would improve the answer's long-term value. – Yannick Huber Aug 01 '18 at 06:09

score 0 · Answer 4 · answered Dec 03 '13 at 14:50

0

Use String.ReplaceAll() instead of this.

But if you only want to remove specific element only you can use substring(). Now you want to know position which you already know.

answered Dec 03 '13 at 14:50

Ruchira Gayan Ranaweera

34,993
17
75
115

i do not want to replace all the occurrences, i want to replace a few of them at certain positions – Hassaan Rabbani Dec 03 '13 at 14:53
please elaborate your answer, what is wrong with my technique? – Hassaan Rabbani Dec 03 '13 at 14:55
@HassaanRabbani I don't see any String replace or remove in your implementation. – Ruchira Gayan Ranaweera Dec 03 '13 at 15:01

score 0 · Answer 5 · answered Dec 03 '13 at 14:56

0

Put your points in a HashSet called set

StringBuilder sb=new StringBuilder();
for(int i=0;i<string.length();i++){
       if(!set.contains(string.charAt(i)))
           sb.append(string.charAt(i));  
 }

 String reformattedString=sb.toString();

answered Dec 03 '13 at 14:56

anguyen

467
4
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A.Sfon · Answer 6 · 2017-06-28T11:01:50.797

First you have to put \ in front of the special characters in order to do the matching of the two string, thus you will have .equals("\"\\n\\t\\t\\t\""), otherwise the substring is not going to be recognized inside the string. Then the other thing which you have to fix is the position of the index begin and end inside .subSequence(k,k+10) since the first and the last character are 10 positions apart and not 4. Note also that when you patch the string you go from position 0 to k and from k+10 to str.length(). If you go from 0 --> k and k --> length() you just join the old string together :). Your code should work like this, I have tested it already

   if(str.substring(k, k+10).equals("\"\\n\\t\\t\\t\""))
        {
     newstr = str.substring(0,k)+str.substring(k+10,(str.length()));
         }

also you don't need +" "+ since you are adding strings. Whoever wants to see the effect of this can run this simple code:

public class ReplaceChars_20354310_part2 {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {


    String str = "This is a weird string containg balndbfhr frfrf br brbfbrf b\"\\n\\t\\t\\t\"";

    System.out.println(str); //print str 

    System.out.println(ReplaceChars(str));  //then print after you replace the substring 

    System.out.println("\n");  //skip line 


    String str2 = "Whatever\"\\n\\t\\t\\t\"you want to put here"; //print str 

    System.out.println(str2);  //then print after you replace the substring

    System.out.println(ReplaceChars(str2));

}


      //Method ReplaceChars

       public static String ReplaceChars (String str) {

       String newstr ="";

       int k;

        k = str.indexOf("\"\\n\\t\\t\\t\""); //position were the string    starts within the larger string

      if(str.substring(k, k+10).equals("\"\\n\\t\\t\\t\""))
        {

       newstr = str.substring(0,k)+str.substring(k+10,(str.length())); //or just str

        }


           return newstr;

        }//end method


     }

Remove characters at certain position at string

6 Answers6