PHP-正则表达式匹配超过两个字母的单词

Question

I'm trying to explode a string into a word array, the condition is that a word is considered as such only if it has two or more letters, what I have is the following, but words with a single letter are still being considered as match:

$input_string = "I have a cake inside my fridge";

$string_array = preg_split("/[^\w{2,}]*([\s]+([^\w{2,}])*|$)/", $input_string, -1, PREG_SPLIT_NO_EMPTY);

But I'm still getting the words "I" and "a", why it isn't working?

Answer 1

If you just want to capture all "words" having 2 or more letters, then just use preg_match_all here:

$input_string = "I have a cake inside my fridge";
preg_match_all("/\b\w{2,}\b/", $input_string, $matches);
print_r($matches[0]);

This prints:

Array
(
    [0] => have
    [1] => cake
    [2] => inside
    [3] => my
    [4] => fridge
)

Answer 2

The reason it is not working is because the pattern [^\\w{2,}]*([\\s]+([^\\w{2,}])*|$) matches only spaces , and then you split on those spaces resulting in an array with all the words. This is due to \\s which matches a whitespace char, and using the negated character class [^\\w{2,}] which also matches whitespace chars.

If you want to use split, you also have to match the single word characters so that they are not part of the result.

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If you must use split, you can match either a single word character surrounded by optional horizontal whitespace characters to remove those as well, or match 1+ horizontal whitespace characters.

\h*\b\w\b\h*|\h+

Regex demo

For example

$input_string = "I have a cake inside my fridge";
$string_array = preg_split("/\h*\b\w\b\h*|\h+/", $input_string, -1, PREG_SPLIT_NO_EMPTY);
print_r($string_array);

Output

Array
(
    [0] => have
    [1] => cake
    [2] => inside
    [3] => my
    [4] => fridge
)

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If you want to match all strings that consist of at least 2 characters, you could also use \\S{2,} with preg_match_all .