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<?php $que = "aa bb33cc 5.po"; echo preg_replace('/(?<=[^0-9,. ])(?=[0-9,.])|(?<=[0-9,.])(?=[^0-9,. ])/',' ',$que) . PHP_EOL; echo preg_replace('/(?|([^0-9,. ])([0-9,.])|([0-9,.])([^0-9,. ]))/','$1 $2',$que) . PHP_EOL; echo preg_replace('/(?:([^0-9,. ])([0-9,.])|([0-9,.])([^0-9,. ]))/','$1$3 $2$4',$que);

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28.44 ms | 404 KiB | 5 Q