Occurences for integer in string

Question

0.00/5 (No votes)

See more:

package RegularEspressions;

import java.util.regex.*; 
 
public class RegFndMultiple { 
  public static void main(String args[]) { 
    Pattern pat = Pattern.compile("^([+-]?[0-9]\\d*|0)$"); 
    Matcher mat = pat.matcher("word 1 2 3 android"); 
 
    while(mat.find()) { 
      System.out.println("numbers found at index " + 
                         mat.start()); 
    } 
  } 
}

should display position of numbers , code that prints the position of integers

What I have tried:

changed code and added new patterns

Posted 23-Feb-18 1:15am

four systems

Updated 23-Feb-18 4:07am

Add a Solution

Comments

Maciej Los 23-Feb-18 7:20am

As to me your pattern is wrong. I'd check: \d{1,}

Patrice T 23-Feb-18 7:33am

What is the question?

2 solutions

Solution 1

Your pattern is wrong, it will match only lines containing an integer and nothing else because of ^ and $.
Pattern would be better as

"([+-]?[0-9]\\d*|0)"

In any cases, the pattern is over complicated, I would use

"([+-]?\\d+)"

Just a few interesting links to help building and debugging RegEx.
Here is a link to RegEx documentation:
perlre - perldoc.perl.org[^]
Here is links to tools to help build RegEx and debug them:
.NET Regex Tester - Regex Storm[^]
Expresso Regular Expression Tool[^]
RegExr: Learn, Build, & Test RegEx[^]
This one show you the RegEx as a nice graph which is really helpful to understand what is doing a RegEx:
Debuggex: Online visual regex tester. JavaScript, Python, and PCRE.[^]

[Update]
Try my pattern and your solution with "test 1 23 -45 test"
You may get surprised.

Posted 23-Feb-18 1:39am

Patrice T

Updated 23-Feb-18 4:14am

v3

Comments

four systems 23-Feb-18 10:00am

cool guys thank you very much

Patrice T 23-Feb-18 10:10am

You are welcome.
If the solution was helpful and the problem is solved, Accept the solution.
It will close the question and tell everyone that the question is answered and no more help is needed.

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

four systems · Accepted Answer · 2018-02-23T04:08:00

Solution 2

package RegularEspressions;

import java.util.regex.*; 
 
public class RegFndMultiple { 
  public static void main(String args[]) { 
    Pattern pat = Pattern.compile("[0-9]"); 
    Matcher mat = pat.matcher("test 1 2 3 test"); 
 
    while(mat.find()) { 
      System.out.println("numbers found at index " + 
                         mat.start()); 
    } 
  } 
}

did this and the result is

numbers found at index 5
numbers found at index 7
numbers found at index 9

Posted 23-Feb-18 4:08am

four systems

Comments

Patrice T 23-Feb-18 10:12am

Try your solution with "test 1 23 -45 test"

four systems 23-Feb-18 10:28am

the result is

numbers found at index 5
numbers found at index 7
numbers found at index 8
numbers found at index 11
numbers found at index 12

Patrice T 23-Feb-18 10:48am

Is it what you expect?
Because I see 3 integers.

four systems 26-Feb-18 4:45am

what it does is checks for each number but as it what the requirement is that check any numbers and put word there, thanks