課后作業aaa
<?php
//str_split分割字符串
//strlen($filename)獲取字符串長度
function?getFileExtension($filename)
{
????$q="";
????$name="";
???$arr=str_split($filename);
???for?($i=strlen($filename)-1;$i>0;$i--)
???{
???????if(?$arr[$i]==".")
???????{
??????????$q=$i;
??????????continue;
???????}
???}
???for($i=$q;$i<strlen($filename);$i++)
???{
?????????$name.=$arr[$i];
???}
???return?$name;
}
echo?getFileExtension("lio.text");
2021-06-03
正則表達式
function?file1($file_name='text.txt'){
????$sss='|\.[\w]+$|';
????$file_name=$file_name;
????$ccc=NULL;
????if(preg_match($sss,$file_name,$match)){
????????$bbb=$match[0];
????????return?$bbb;
????}else{
????????return?$ccc;
????}
echo?file1('1');
echo?"<br>";
var_dump(file1('a.php.html'));
2021-01-16
這個效率高些
function?getExt($filename){ ????$pos?=?strripos($filename,"."); ????if(!$pos){ ????????return?"擴展名不存在！"; ????}else?{ ????????return?substr($filename,?$pos?+?1); ????} }2020-10-10
<?php?
function?getHouZhui($filename){
????$result?=?explode(".",$filename);
????$num?=?count($result);
????return?$result[$num-1];
}
echo?getHouZhui("1.php.html");
?>