PHP-单独的大小写字符

Question

I want to separate upper or lower case characters.

In this text : "HELLO WORLD how are you"

I want to have in the first variable : "HELLO WORLD" and "how are you" in the second.

How can I do that with php ?

Thanks a lot

Answer 1

This is assuming that the first part of the string is uppercase and the rest is normal (eg mixed case). Like in the example you posted.

preg_match('/^([A-Z\s]+)(.*)$/', $string, $match);
$first_part = trim($match[1]);
$second_part = trim($match[2]);

If uppercase and mixed case words are mixed in the sentence, then I would do it as such (note, this replaces everything between words with single spaces).

$words = preg_split('/[^\w]+/', $string);
$upper = '';
$lower = '';

foreach ($words as $word) {
    if ($word == strtoupper($word)) {
        $upper .= ' ' . $word;
    } else {
        $lower .= ' ' . $word;
    }
}

Answer 2

If your input string is always an UPPER CASE SEQUENCE followed by a lower case sequence , something like this might do it

if (preg_match('/^([A-Z\s]+)\s+([a-z\s+])$/', $str, $matches))
{
   $upper=$matches[1];
   $lower=$matches[2];

}

To walk through that regex

• ^ anchors the match the to start of the string, so that we test the entire string
• ( opening parenthesis begins a group we can extract later as $matches[1]
• [AZ\\s] is a character class to match chars which are A through Z or whitespce
• + makes sure there is one or more such chars
• ) closes the first group
• then we match a little more whitespace before looking for the lower case part in a similar fashion
• $ anchors the match to the end of the string, so that we can be sure we've considered the entire string

Answer 3

Just to use a different, non-regexp approach

$original = "HELLO WORLD how are you";

$upper = trim(implode(array_intersect(str_split($original),str_split(strtoupper($original)))));
$lower = trim(implode(array_intersect(str_split($original),str_split(strtolower($original)))));

echo $upper,'<br />';
echo $lower,'<br />';

Answer 4

Although regexp is best method for determine upper or lower, also you can use this function, for understand whether upper or lower of a character. If string that been sent as parameter includes completely upper, this function will return true value

function is_upper($str)
{
$str2=strtoupper($str);
$$str="x";
if($$str==$$str2)
{

return true;

}
else
return false;
}

Answer 5

I know this is a bit late, but I stumbled across this question while looking for something else. Anyway, preg_split works for this situation:

$original = "HELLO WORLD how are you";

$split = preg_split(
    '/([[:lower:]].*)/',
    $original,
    0,
    PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY
);

print_r($split);

Outputs:

Array
(
    [0] => HELLO WORLD 
    [1] => how are you
)