PHP preg_split：由其他字符串拆分字符串

I want to split a large string by a series of words.

我想用一系列单词拆分一个大字符串。

E.g.

$splitby = array('these','are','the','words','to','split','by');
$text = 'This is the string which needs to be split by the above words.';

Then the results would be:

然后结果将是:

$text[0]='This is';
$text[1]='string which needs';
$text[2]='be';
$text[3]='above';
$text[4]='.';

How can I do this? Is preg_split the best way, or is there a more efficient method? I'd like it to be as fast as possible, as I'll be splitting hundreds of MB of files.

我怎样才能做到这一点? preg_split是最好的方法,还是有更有效的方法?我希望它尽可能快,因为我将分割数百MB的文件。

4 个解决方案

#1

I don't think using pcre regex is necessary ... if it's really splitting words you need.

我不认为使用pcre正则表达式是必要的......如果它真的分裂了你需要的单词。

You could do something like this and benchmark see if it's faster / better ...

你可以做这样的事情和基准测试看看它是否更快/更好......

$splitby = array('these','are','the','words','to','split','by');
$text = 'This is the string which needs to be split by the above words.';

$split = explode(' ', $text);
$result = array();
$temp = array();

foreach ($split as $s) {

    if (in_array($s, $splitby)) {
        if (sizeof($temp) > 0) {
           $result[] = implode(' ', $temp);
           $temp = array();
        }            
    } else {
        $temp[] = $s;
    }
}

if (sizeof($temp) > 0) {
    $result[] = implode(' ', $temp);
}

var_dump($result);

/* output

array(4) {
  [0]=>
  string(7) "This is"
  [1]=>
  string(18) "string which needs"
  [2]=>
  string(2) "be"
  [3]=>
  string(5) "above words."
}

The only difference with your output is the last word because "words." != "word" and it's not a split word.

与输出的唯一区别是最后一个词,因为“单词”。 !=“单词”,这不是分词。

#2

This should be reasonably efficient. However you may want to test with some files and report back on the performance.

这应该是合理有效的。但是,您可能希望使用某些文件进行测试并报告性能。

$splitby = array('these','are','the','words','to','split','by');
$text = 'This is the string which needs to be split by the above words.';
$pattern = '/\s?'.implode($splitby, '\s?|\s?').'\s?/';
$result = preg_split($pattern, $text, -1, PREG_SPLIT_NO_EMPTY);

Regular Expression Demo: http://rubular.com/r/jNUO1KvrXg

正则表达式演示:http://rubular.com/r/jNUO1KvrXg

PHP Code Demo: http://www.ideone.com/ov3Wl

PHP代码演示:http://www.ideone.com/ov3Wl

#3

preg_split can be used as:

preg_split可以用作:

$pieces = preg_split('/'.implode('\s*|\s*',$splitby).'/',$text,-1,PREG_SPLIT_NO_EMPTY);

See it

#4

-1

Since the words in your $splitby array are not regular expression maybe you can use

由于$ splitby数组中的单词不是正则表达式,您可以使用

str_split

#1