php模式匹配

Question

I want to get the part of the string before the last occurance of "-",

for example,

$string1 = 'a-b-c-de-f-gfgh';

I want to get this part returned: abc-de-f. Of course, I don't know the length of the last part.

What is the easy way to do it?

Thank you

Answer 1

echo substr ($string1, 0, strrpos ($string1, '-'));

strrpos（）查找子字符串的最后一次出现-在这种情况下，substr（）按照strrpos（）的定义，将原始字符串从第0个字符拆分到第n个字符

Answer 2

使用strrpos（）获取最后一个“-”的位置，并对其进行substr（） ：

echo substr($string1, 0, strrpos($string1, "-"));

Answer 3

get the last occurrence of - using $x = strrpos($string1,'-'); then use substr() to return the decired string from 0 to $x

 echo substr ($string1, 0, $x);

Answer 4

As an alternative to the other posters:

preg_match('/(.*)-[^-]+/', 'a-b-c-de-f-gfgh', $result);

Result:

Array
(
    [0] => a-b-c-de-f-gfgh-a
    [1] => a-b-c-de-f-gfgh
)

Though I like Jeroens solution more.

Answer 5

您可以删除最后一部分：

$string = preg_replace("|-[^-]+$|", "", $string);