Get Substring from a String from __

Question

I want to extract subString from a String, starting from __(Double UnderScore) till a "(Double Quotes) or special character '[](),' is found.

I have been at it for some while now but cannot figure it out.

For Example: Input String : "NAME":"__NAME"

Required String : __NAME

Thanks for your time.

1. find the position of `__` 2. substring from that position. 3. in the new string: find the position of `"`. 4. substring until that position — ParkerHalo, Aug 02 '17 at 10:42

score 4 · Accepted Answer · answered Aug 02 '17 at 10:44

You can use this regex (__(.*?))[\"\[\]\(\),] to get what you want you can use :

String str = "\"NAME\":\"__NAME\"";
String regex = "(__(.*?))[\"\\[\\]\\(\\),]";
Pattern pattern = Pattern.compile(regex);
Matcher matcher = pattern.matcher(str);

while (matcher.find()) {
    System.out.println(matcher.group(1));
}

Output

__NAME

regex demo

score 0 · Answer 2 · answered Aug 02 '17 at 10:56

0

You could try following code

String input="\"NAME\":\"__NAME\"";
int startIndex=input.indexOf("__");
int lastIndex=input.length();
String output=input.substring(startIndex, (lastIndex-1));
System.out.println(output);

answered Aug 02 '17 at 10:56

Prafull

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1
11

i think the algorith from @ParkerHalo describes a better solution... – Martin Frank Aug 02 '17 at 11:04

score 0 · Answer 3 · answered Aug 03 '17 at 08:03

May this solution help you:

import java.util.*;
class test
{
    public static void main(String[] args) {
        Scanner s=new Scanner(System.in);
        String a=s.next();
        int i=a.indexOf("__");
        int j=a.indexOf('"',i);
        System.out.println(a.substring(i,j));
       }
}

In this firstly we calculate the index of __ and then we calculate the index of " after __.and then use substring method to get desired output.

Get Substring from a String from __

3 Answers3