分割字符串

Question

怎样将这个字符串SmithDaniel分成2个单词？
即：Smith和Daniel

Answer 1

$str = "SmithDaniel";
preg_replace("/^([A-Z][a-z]*)([A-Z][a-z]*)/","$1 $2",$str)

Answer 2

<?php
$str = 'SmithDanielSaaaDbbb';
$str = explode(',',preg_replace('/(?<!^)[A-Z]/',',\0',$str));
print_r($str);
?>

Answer 3

$str = "SmithDaniel";
$s = preg_replace("/([A-Z])/"," $1",$str);
echo $s;