Question

我正在尝试修改此正则表达式模式，以便它不允许连续两个指定的字符或开头/结尾 -

/^[^\!\"\£\$\%\^\&\*\(\)\[\]\{\}\@\~\#\/\>\<\\\*]+$/

所以目前它在字符串中的任何地方阻止了这些字符，但我也希望阻止以下字符发生：

在字符串结尾处出现的任何空格，撇号'，下划线_或连字符-或点.
< / LI>
还会连续阻止这两个字符，即''或_._或' -__- ' .

非常感谢任何帮助。

非常感谢

Answer 1

单程

/^(?=[^!"£$%^&*()[\]{}@~#\/><\\*]+$)(?!.*[ '_.-]{2})[^ '_.-].*[^ '_.-]$/

注意，仅测试为javascript正则表达式，即

var rex = /^(?=[^!"£$%^&*()[\]{}@~#\/><\\*]+$)(?!.*[ '_.-]{2})[^ '_.-].*[^ '_.-]$/;
rex.test('okay');        // true
rex.test('_not okay');   // false

或者，匹配不允许的模式

/^[ '_.-]|[ '_.-]$|[!"£$%^&*()[\]{}@~#\/><\\*]|[ '_.-]{2}/

第一个正则表达式只匹配不包含不允许模式的字符串上面的那个将匹配字符串中的任何不允许的模式。

更新

现在使用php进行简要测试。唯一的区别是字符集中的"需要转义。

<?php
$test = 'some string';
$regex = "/^[ '_.-]|[ '_.-]$|[!\"£$%^&*()[\]{}@~#\/><\\*]|[ '_.-]{2}/";
if ( preg_match( $regex, $test ) ) {
    echo 'Disallowed!';
}

Answer 2

我不确定我是否理解确切的问题，但这是一个建议：

<?php
$test     = "__-Remove '' _._ or -__- but not foo bar '. _  \n";
$expected = 'Remove or but not foo bar';

// The list of disallowed characters. There is no need to escape.
// This will be done with the function preg_quote.
$excluded_of_bounds = "'_.-";

// Remove disallowed characters from start/end of the string.
// We add the space characters that should not be in the regexp.
$test = trim($test, $excluded_of_bounds . " \r\n");

// In two passes
$patterns = array(
  // 1/ We remove all successive disallowed characters,
  //    excepted for the spaces
  '#[' . preg_quote($excluded_of_bounds) . ']{2,}#',
  // 2/ We replace the successive spaces by a unique space.
  '#\s{2,}#',
);
$remplacements = array('', ' ');

// Go!
$test = preg_replace($patterns, $remplacements, $test);

// bool(true)
var_dump($expected === $test);

Answer 3

$tests[1]     = "fail_.fail";  // doubles
$tests[]     = "fail_-fail";
$tests[]     = "fail_ fail";
$tests[]     = "fail  fail";
$tests[]     = "fail -fail";
$tests[]     = "pas.s_1";
$tests[]     = "pa.s-s_2"; // singles
$tests[]     = "pas.s_3";
$tests[]     = "p.a.s.s_4";
$tests[10]     = "pa s-s_5";
$tests[]     = "fail fail'"; // pre or post-pended
$tests[]     = " fail fail";
$tests[]     = " fail fail";
$tests[]     = "fail fail_";
$tests[15]     = "fail fail-";

// The list of disallowed characters. There is no need to escape.
// This will be done with the function preg_quote.
$exclude = array(" ","'", "_", ".", "-");

$pattern =  "#[" . preg_quote(join("", $exclude)) . "]{2,}#s";

// run through the simple test cases 

foreach($tests as $k=>$test){
if( 
    in_array(substr($test, 0, 1), $exclude)  
 || in_array(substr(strrev($test), 0 , 1) , $exclude))
   {
   echo "$k thats a fail" . PHP_EOL;
   continue;
   }

  $test = preg_match( $pattern,  $test);
    if($test === 1){
    echo "$k - thats a fail". PHP_EOL ;
    }else{
    echo "$k - thats a pass $test ". PHP_EOL ;
    }
}

从其他回复中无可救药地窃取，我主张使用PHP简单的in_array来首先检查字符串的开头和结尾，然后在发现不好的事情时尽早失败。

如果测试结束，那么运行一个非常简单的正则表达式。

将该批次粘贴到一个函数中并在失败时返回false - 这将是我添加的相当多的冗长行 - 您甚至可以将排除数组作为变量发送 - 但它看起来似乎是一个特定的函数所以可能是YAGNI

例如

if( badString($exclude_array, $input) ) // do stuff

正则表达式连续两个字符不允许

3 个答案: