将字符串转换为大写，除了php中的字符串中的字符串[关闭]

Question

How to covert string to uppercase except the string in () in php

For example: abc(abc)(ABC)(abc)abc >>>change to>>> ABC(abc)(ABC)(abc)ABC

....
$str = 'abc(abc)(ABC)(abc)abc abc(abc)';
function toupper($str) {

???

}
....

Answer 1

Provided the string pattern remains consistent,

function toUpper($str)
{
   $exp = explode('(', $str);
   $to_up = strtoupper($exp[0]);
   $inside_brackets = '('.$exp[1];
   return $to_up.$inside_brackets;
}

echo toUpper("abc(def)");

DEMO