正則表達式與給定字符旁邊的第一個數字匹配

Question

如何匹配％字符旁邊的第一個數字？

<?php 
$string = 'Get 30% off when you spend over £100 on electronics'; 

if(strpos($string,'% off') !== false) { 
     $number = preg_replace("/[^0-9%]/", '', $string); 
     return $number; 
} 

這將返回30％，100

任何幫助將是巨大的在此先感謝。

Answer 1

此正則表達式匹配（和捕獲）全數字 '％' 號之前：

'/(\d+)%/' 

你可以試一下像這樣：

$string = 'Get 30% off when you spend over £100 on electronics'; 
preg_match('/(\d+)%/', $string, $matches); 
print_r($matches[1]); 

請讓我們知道您的要求是否更加複雜。

Answer 2

正則表達式：

\d{1,3}% 

解釋：

\d{1,3} match a digit [0-9] 
    Quantifier: {1,3} Between 1 and 3 times, as many times as possible, giving back as needed [greedy] 
% matches the character % literally 

Answer 3

這似乎做:)

if(strpos($string,'%') !== false) { 
     $regex_percent = "/((\d{1,5})(?:%))/"; 
     preg_match($regex_percent, $string, $matches_off); 
     $number = $matches_off[2]; 

     return $number; 
    }