Find the position of the first occuring of any number bigger than certain number in a string

Question

I have this string: "20 plus 1000 is not 20000."

And I want to get the position of the first number bigger than 10000.

I'm actualy (and for a different purpose) using this first answer code to get the position of the first number in my string:

function firstNumPos($text){
  preg_match('/^\D*(?=\d)/', $text, $m);
  return isset($m[0]) ? strlen($m[0]) : false;
}

But it doesn't distinguish between number sizes, so, what could be missing for this function to get the position of the first occurence of a number bigger than 10000?

Any solution is welcome, not necessarily by using that function.

your expected output is `21`? – A l w a y s S u n n y Feb 19 '19 at 15:40 — A l w a y s S u n n y, Feb 19 '19 at 15:40

Filip Š · Answer 1 · 2019-02-19T17:44:34.347

1

You can get all the numbers with regex and then loop them and find the first bigger than 10000.

function getNumberPosition($text, $min = 10000){
    preg_match_all('!\d+!', $text, $matches);

    foreach ($matches[0] as $match) {
        if ($match >= $min) {
            return strpos($text, $match);
        }
    }
}

echo getNumber('20 plus 1000 is not 20000.');

edited Feb 19 '19 at 17:44

answered Feb 19 '19 at 15:41

Filip Š

746
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nice function but where's the position? – Roberto Sepúlveda Bravo Feb 19 '19 at 16:03
1

@Roberto Sepúlveda Bravo Sorry, I missed the part about the position in question. I fixed answer so it now gets a position. – Filip Š Feb 19 '19 at 18:11

V-K · Accepted Answer · 2019-02-19T16:18:14.777

1

function firstNumPos($text, $number){
  preg_match_all('!\d+!', $text, $match);
  foreach ($match[0] as $value) {
      if ($value > $number) {
          return strpos($text, $value);
      }
  }
}

echo firstNumPos('20 plus 1000 is not 20000.', 10000);

edited Feb 19 '19 at 16:18

answered Feb 19 '19 at 15:44

V-K

1,297
10
28

A l w a y s S u n n y · Answer 3 · 2019-02-19T16:17:01.820

1

If I don't misunderstood your question then you can try this way without using any fancy regex, Let's do it simple php way,

<?php
function findFirstOccurance($str){
    $arr = explode(' ',$str);
    $counter = 0;
    foreach($arr as $value){
        $counter=$counter+strlen($value);
        if($value > 10000){
            return $counter - 1;
        }
    }
}
$str = "20 plus 1000 is not 20000.";
echo findFirstOccurance($str);
?>

DEMO: https://3v4l.org/NNDZk

edited Feb 19 '19 at 16:17

answered Feb 19 '19 at 15:45

A l w a y s S u n n y

36,497
8
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why it returns 21 and not 20? – Roberto Sepúlveda Bravo Feb 19 '19 at 16:07
1

@RobertoSepúlvedaBravo Actually I was not sure what you wanted as output. Also added a comment for you beneath the question you asked. To get the output as 20, I've **Edited** my answer have a look again – A l w a y s S u n n y Feb 19 '19 at 16:16

Jc Nolan · Answer 4 · 2019-02-19T16:59:03.780

1

Simply use this regex

\d\d\d\d\d\d*

to pull out matches on all numbers with 5 digits or more. Then you can simply check for the first match and return it

function getFirstOccr($srcStr, $places=5)
{
//    $matchStr = '\d{'.$places.'}\d*';
    $matchStr = str_repeat('\d', $places).'\d*';
    preg_match('/'.$matchStr.'/', $srcStr, $matches);

    return isset($matches[0]) ? strpos($srcStr,$matches[0]) : false;
}

$srcStr = "20 plus 1000 is not 20000.";
print getFirstOccr($srcStr,5);

I believe this should be most computationally efficient

edited Feb 19 '19 at 16:59

answered Feb 19 '19 at 15:51

Jc Nolan

450
4
15

Ah, sorry I was coding off the top of my head and have been exclusively working in Swift the past 3 years. It is fixed and checked now and added the option for the alternate regex someone else recommend. This code with that regex should be the most efficient I believe – Jc Nolan Feb 19 '19 at 17:00

score 0 · Answer 5 · answered Feb 19 '19 at 15:51

If you are always going to use 10000, it may be easy enough to look for the first 5 digit number using \d{5} and if you want the character position, then use PREG_OFFSET_CAPTURE...

function firstNumPos($text){
    preg_match('/(\d{5})/', $text, $m, PREG_OFFSET_CAPTURE);
    return isset($m[0]) ? $m[0][1] : false;
}

echo firstNumPos('20 plus 1000 is not 20000.');

Find the position of the first occuring of any number bigger than certain number in a string

5 Answers5

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