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Norak
Asked: 2020-06-01 04:02:01 +0800 CST 2020-06-01 04:02:01 +0800 CST

Extract part of a string that meets regular expression (RegEx)

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I need to extract a substring from a string that meets a number of conditions . I have almost succeeded, but I have an error in the regular expression and I do not finish obtaining the desired result.

I receive a string, with a long name of a rate, along with a letter and version number. For example: "NAME RATE V1 12M". I need to keep only the "V1" part.

It will always follow the pattern: - A letter (in principle capitalized, although I would like to accept both), in my case it will always be the letters: V, L, M. - Always followed by a number that starts at 0 and can be up to 2 digits . Here I have my problem, when it is a figure, it extracts the substring correctly, when it is 2 figures it fails and it does not extract it, it does not find a match.

I leave you what I have so far with some examples included:

$var1 = "TARIFA 1.1 NOMBRE TARIFA V1 12M";
$var2 = "TARIFA LDVB8 NOMBRE V5 10M";
$var3 = "TARIFA HD76 V10 12M";
$var4 = "TARIFA NOMBRE4 L3 18M";
$var5 = "TARIFA NOMBRE5 L10 12M";
$var6 = "NO HAY COINCIDENCIA";
$var7 = "TARIFA NOMBRE7 M6 12M";

function extractV($str) {
    if (preg_match('/ [V|L|M][0-9]? /',$str,$coincidencias,PREG_OFFSET_CAPTURE)) {
        //Hay coincidencia
        $valorBuscado = $coincidencias[0];
        $version = $valorBuscado[0];
    } 
    else 
    {
        $version = "NO";
    }
    return $version;
}

$extraccion1 = extractV($var1);
echo "<br>Coincidencias1 = ". $extraccion1;

$extraccion2 = extractV($var2);
echo "<br>Coincidencias2 = ". $extraccion2;

$extraccion3 = extractV($var3);
echo "<br>Coincidencias3 = ". $extraccion3;

$extraccion4 = extractV($var4);
echo "<br>Coincidencias4 = ". $extraccion4;

$extraccion5 = extractV($var5);
echo "<br>Coincidencias5 = ". $extraccion5;

$extraccion6 = extractV($var6);
echo "<br>Coincidencias6 = ". $extraccion6;

$extraccion7 = extractV($var7);
echo "<br>Coincidencias7 = ". $extraccion7;

As you can see, in the $var3and $var5, it does not extract value (because the number that follows the letter is 2 figures), but it should. How can I correct the RegEx? Or any solution for substring extraction with those features? Thank you!

php

1 Answers

  1. Best Answer

    You're just asking for a numeric character followed by a space, which doesn't hold if there are two.

    It should be instead

    preg_match('/ ([V|L|M][0-9]{1,2})? /',$str,$coincidencias,PREG_OFFSET_CAPTURE);

    to accept either one or two figures. I also wrapped it in parentheses so that the second element of the array is the captured group without the spaces.

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