达维营-前端网1.单字节字符串反转
php提供了现成的用于字符串反转的函数strrev()
$str = 'abcdef123'; echo strrev($str)
2.对于包含中文的多字节字符串需要用到mb_substr()
$str = '字符串反转';
function rev($str, $encoding = 'utf-8'){
$len = mb_strlen($str);
$result = '';
for ($i = $len-1; $i>=0; $i--){
$result.= mb_substr($str,$i,1,$encoding);
}
return $result;
}
echo rev($str);
$str = 'abcdefg123';
$len = strlen($str);
$times = $len/2;
for($i = 0;$i <= $times; $i++ ){
$tmp = $str[$i];
$str[$i] = $str[$len-$i-1];
$str[$len-$i-1] = $tmp;
}
echo $str;