CODEWITHSUNDEEP
javaandroidstring
Lorenzo Calosi
Lorenzo Calosi

Reputation: 53

Is there a way to extract a value from a string which is separated by a certain character?

My app reads a value of a NFC tag which contains plain text, to then cut the read String up. The string should be as follow: "r=v;b=v;g=v;n=v;p=v;m=v;s=v" I want to read the "v" characters, since they are divided by the ; character, and i remember there being a function that let me divide strings like this, how do i do it? The v value isn't constant, it could span 1 position like it could span 3 or 4. The app is for Android phones, written in Java on Android Studio.

Upvotes: 1

Views: 162

Answers (4)

Nikita Kurtin
Nikita Kurtin

Reputation: 6237

You are asking about String method .split()

it's splits string into array and so for you question, since split can work with regex you can split exactly for needed patterns like this:

String givenString="r=v;b=v;g=v;n=v;p=v;m=v;s=v";
        String[]vs=givenString.split("([;]?[a-z]{1}[=])");
        for(String v: vs){System.out.println(v);}//prints all v

Regex explanation:

  1. [;]? -> means may start with one semicolon or none
  2. [a-z]{1} -> means one letter lower case only
  3. [=] -> means equals sign

Edit: if you use split by only semicolon (as @cvester suggested), you get the whole entry string, such as: "r=v","b=v", etc.. in this case you can iterate over all entries and then make one more split by equals "=" like this:

String []entries=givenString.split(";");
        for (String entry:entries){
            String []vs=entry.split("=");
            System.out.println(vs[1]);//prints all v
        }

Upvotes: 2

jozzy
jozzy

Reputation: 2943

You could use regex to avoid looping

String input = "r=v;b=v;g=v;n=v;p=v;m=v;s=v";
input.trim().replaceAll("([a-zA-Z]=)+","").replaceAll(";",""));

Upvotes: 0

Uma Kanth
Uma Kanth

Reputation: 5629

Use String#split() or you could create your own logic.

String string = "r=v;b=asfasv;g=v;n=asf;p=v;m=v;s=vassaf";
    String word = "";
    int i = 0;
    ArrayList<String> list = new ArrayList();
    while(i < string.length())
    {
      if(string.charAt(i) == '=')
       {
           i++;
         while( i < string.length() && string.charAt(i) != ';' )
            {
              word += string.charAt(i);
              i++;
            }
         list.add(word);
         System.out.println(word);
         word = "";
       } 
      i ++;
    }
    if(!word.equals(""))
     list.add(word);

    System.out.println(list);

Upvotes: 0

cvesters
cvesters

Reputation: 696

Java has a split function on a String. http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#split(java.lang.String)

So you can just use split(";");

Upvotes: 2

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