拆分具有多个分隔符的字符串

问题描述：

I have seen many (before you go flagging this as a duplicate) on how to do this, but for some reason my output isn't working:

// $delimiters wanted: ', ' | '; ' | ',' | ';' | ' , ' | ', and ' | ' and ' | ',and '
$str = 'Name 1, Name 2; Name 3;Name4 , Name 5,Name 6, and Name 7,and Name 8 and Name 9';
$delimiter = array(
    ', ',
    '; ',
    ';',
    ',',
    ' , ',
    ', and ',
    ' and ',
    ',and '
);
$str_new = explode( $delimiter[0], str_replace($delimiter, $delimiter[0], $str) );

However, when I output the array, I get this:

<?php foreach($str_new as $new) { echo 'a' . $new; } ?>

Array (
    [0] => Name 1
    [1] => Name 2
    [2] => Name 3
    [3] =>        // WHY IS THIS EMPTY?
    [4] => Name 4
    ...
)

So is there a better way to match the delimiters I have listed?

我已经看到很多（在你将其标记为副本之前）如何做到这一点，但由于某种原因我的输出不起作用： p>

  // $ delimiters wanted：'，'|  “;  '|  '，'|  ';'  |  '，'|  '和'|  '和'|  '，'和'
 $ str ='名称1，名称2; 名称3;名称4，名称5，名称6和名称7，名称8和名称9'; 
 $ delimiter = array（
'，'，
';'，
';'，
  '，'，
'，'，
'和'，
'和'，
'和'
）; 
 $ str_new = explode（$ delimiter [0]，str_replace（$ delimiter）  ，$ delimiter [0]，$ str））; 
  code>  pre> 
 
 但是，当我输出数组时，我得到了这个： p> 
 
  ＆lt;？php foreach（$ str_new as $ new）{echo'a'。 美元的新;  }？＆gt; 
 
Array（
 [0] =＆gt;名称1 
 [1] =＆gt;名称2 
 [2] =＆gt;名称3 
 [3] =＆gt; //为什么 这是空吗？
 [4] =＆gt;名称4 
 ... 
）
  code>  pre> 
 
 
那么是否有更好的方法来匹配分隔符我 已列出？ p> 
  div>

答

I'd use regexp like this in your case:

preg_split('/,? ?and | ?[,;] ?/', $str)

You may also want to replace spaces by \s if the other space characters may appear (like TAB, for example) or even \s* instead of ? to cover the case of multiple spaces.

答

Have you tried something like this from php.net?

<?php

//$delimiters has to be array
//$string has to be array

function multiexplode ($delimiters,$string) {

    $ready = str_replace($delimiters, $delimiters[0], $string);
    $launch = explode($delimiters[0], $ready);
    return  $launch;
}

$text = "here is a sample: this text, and this will be exploded. this also | this one too :)";
$exploded = multiexplode(array(",",".","|",":"),$text);

print_r($exploded);
?>

Or something like Split String by Multiple Delimiters in PHP

答

In your code, between Name 6, and Name 7, first the , gets replaced, then the and.

Therefore you end up with this string:

Name 1, Name 2, Name 3, Name4, Name 5, Name 6, , Name 7, Name 8, Name 9

Hence, the empty value...

Clean your result array before outputting and you should be fine:

$str_out = array_filter($str_new);

答

The problem in your approach is, that you want to solve a problem using the wrong way. Even if you manage to create a list of delimiters, what happens if you need e.g. separate the words by another character, let's say, a '$' sign?

You should implement a tokenizer/lexer which reads the input char by char and distinguishes between white spaces, terminal and non terminal symbols/characters. The lexer would then generate a sequence of token, e.g.

STRING-SYMBOL:'NAME1' 
KOMMA-SYMBOL 
AND-SYMBOL 
STRING-SYMBOL:'NAME2' 
SEMICOLON-SYMBOL 
STRING-SYMBOL:'NAME3' 
AND-SYMBOL
...
EOF-SYMBOL

You then simply filter out any non STRING-SYMBOL symbols (or you combine strings using the AND-SYMBOL. This is (imho) the only rock solid solution. It is also very easy to extend and to generalize: Once you have written a nice tokenizer/lexer, you can use this approach for almost any string analyzing problem.

Writing a tokenizer is generally very simple: It scans the input char by char and first categorizes the char. It implements a simple state machine to collect characters which will form a symbol.

You may try to implement this using a regex, which should be possible as well. Anyway, the tokenizer will generate a list of token (or will retrieve the next one upon request). The last token it will retrieve is the EOF-TOKEN indicating that the input sequence has been fully traversed.

拆分具有多个分隔符的字符串

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