正则表达式仅允许字符串中包含整数和逗号

Question

有谁知道 preg_replace 对于只允许整数和逗号的字符串来说是什么？我想删除所有空格、字母、符号等，因此剩下的只是数字和逗号，但字符串中没有任何前导或训练逗号。 （示例：5,7,12）

这是我现在使用的，它只删除逗号前后的空格，但我认为允许其他任何内容。

$str = trim(preg_replace('|\\s*(?:' . preg_quote($delimiter) . ')\\s*|', $delimiter, $str));

Answer 1

这应该可以满足您的需要：

$str = preg_replace(
  array(
    '/[^\d,]/',    // Matches anything that's not a comma or number.
    '/(?<=,),+/',  // Matches consecutive commas.
    '/^,+/',       // Matches leading commas.
    '/,+$/'        // Matches trailing commas.
  ),
  '',              // Remove all matched substrings.
  $str
);

Answer 2

这是您问题的答案：

//drop all characters except digits and commas
    preg_match_all('/[\\d,]/', $subject, $result, PREG_PATTERN_ORDER);
    $result = implode('', $result[0]);

//strip the empty or trailing commas
    if( preg_match('/^,*(\\d.*?\\d),*$/', $result, $regs) ){
        $result = $regs[1];
    }

但是您可能想改用这个函数？

听起来像是我曾经写过的一个函数。请参阅： https://github.com/homer6/altumo /blob/master/source/php/Validation/Arrays.php

/**
* Ensures that the input is an array or a CSV string representing an array.
* If it's a CSV string, it converts it into an array with the elements split 
* at the comma delimeter.  This method removes empty values. 
* 
* Each value must be a postitive integer.  Throws and exception if they aren't
* (doesn't throw on empty value, just removes it).  This method will santize
* the values; so, if they're a string "2", they'll be converted to int 2.
* 
* 
* Eg.
*     sanitizeCsvArrayPostitiveInteger( '1,2,,,,3' );   //returns array( 1, 2, 3 );
*     sanitizeCsvArrayPostitiveInteger( array( 1, 2, 3 ) );   //returns array( 1, 2, 3 );
*     sanitizeCsvArrayPostitiveInteger( array( 1, "hello", 3 ) );   //throws Exception
*     sanitizeCsvArrayPostitiveInteger( '1,2,,"hello",,3' );   //throws Exception
* 
* @param mixed $input
* @throws Exception //if $input is not null, a string or an array
* @throws Exception //if $input contains elements that are not integers (or castable as integers)
* @return array
*/
static public function sanitizeCsvArrayPostitiveInteger( $input );

Answer 3

我知道这并不是您真正想要的，但每次我尝试它时它都会返回格式正确的字符串。

$string = ", 3,,,,, , 2 4 , , 3 , 2 4 ,,,,,";
//remove spaces
$string = preg_replace("[\s]","",$string);
// remove commas
$array = array_filter(explode(",",$string));
// reassemble
$string = implode(",",$array);

print_r($string);

返回3,24,3,24

Answer 4

这是我在大家的帮助下想出的功能。它适用于逗号，但不适用于任何其他分隔符。

if (!function_exists('explode_trim_all')) {
  function explode_trim_all($str, $delimiter = ',') {
    if ( is_string($delimiter) ) {
      $str = preg_replace(
        array(
          '/[^\d'.$delimiter.']/', // Matches anything that's not a delimiter or number.
          '/(?<='.$delimiter.')'.$delimiter.'+/', // Matches consecutive delimiters.
          '/^'.$delimiter.'+/',                   // Matches leading delimiters.
          '/'.$delimiter.'+$/'                    // Matches trailing delimiters.
        ),
        '',              // Remove all matched substrings.
        $str
      );
      return explode($delimiter, $str);
    }
    return $str;
  }
}