PHP:获取给定格式化字符串末尾的数值
我“继承”了一个有缺陷的 PHP 页面。我不是这门语言的专家,但我想我找到了错误的根源。在一个循环中,页面向服务器发送一个格式化的字符串:我在 HTML 页面中找到的字符串如下所示:
2011-09-19__full_1
所以,看起来我们有三个部分:
- 日期 (0,10);日期 (0,10);
- 字符串 (10,6);
- 最终数字 (17,1);
处理这种情况的代码如下:
$datagrid[] = array("date"=>substr($post_array_keys[$i], 0, 10),"post_mode"=>substr($post_array_keys[$i], 10, 6),"class_id"=>substr($post_array_keys[$i], 17, 1),"value"=>$_POST[$post_array_keys[$i]]);
发生了什么:最终数字可以包含多个字符,因此这一段:
"class_id"=>substr($post_array_keys[$i], 17, 1)
不正确,因为它似乎只检索从第 17 个字符开始的一个字符(这似乎会导致网站出现奇怪的行为)。
作为字符串的最后一部分的整数,要获取整个数字我可以这样安全地更改此行吗?
"class_id"=>substr($post_array_keys[$i], 17, strlen($post_array_keys[$i])-17);
I "inherited" a buggy PHP page. I'm not an expert of this language but I think I found the origin of the bug. Inside a loop, the page sends a formatted string to the server: the string I found in the HTML page is like this one:
2011-09-19__full_1
so, it seems we have three parts:
- a date (0,10);
- a string (10,6);
- a final number (17,1);
The code the handles this situation is the following:
$datagrid[] = array("date"=>substr($post_array_keys[$i], 0, 10),"post_mode"=>substr($post_array_keys[$i], 10, 6),"class_id"=>substr($post_array_keys[$i], 17, 1),"value"=>$_POST[$post_array_keys[$i]]);
What happens: the final number can contain more than one character, so this piece:
"class_id"=>substr($post_array_keys[$i], 17, 1)
is not correct because it seems to retrieve only one character starting from the 17th (and this seems to cause strange behaviors to the website).
Being the whole number the last part of the string, to get the entire number could I safely change this line this way?
"class_id"=>substr($post_array_keys[$i], 17, strlen($post_array_keys[$i])-17);
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如果按照您建议的方式更改代码,您将获得从位置 17 开始的末尾数字。原始代码仅获得第一位数字。您的代码将获得所有数字。
看来你做了功课,这一行
确实给了你一个很好的线索,告诉你你应该在变量中期待什么:
如果你还确认有时 class_id 可以超过 1 个字符,你建议的更改将为你提供完整的 class_id结束。
祝你好运。
If you change the code the way you suggest you would get the numbers at the end starting in position 17. The original code gets only the first digit. Your code would get all the digits.
And it seems you did your homework the line
does give you a very good clue of what you should expect in the variable:
If you also confirmed that sometimes the class_id can be more than 1 char, your suggested change would give you the complete class_id at the end.
Good luck.
您可以使用
此函数返回一个数组,其中字符串中的元素由“_”分隔。
我建议这样做是因为双下划线可能会隐藏在该特定情况下为空的另一个值。
you could use
this functions returns an array with the elements in the string delimited by "_".
I suggest this because the double underscore may hide another value that is empty in that particular case.
如果只是最后一个整数造成问题,您可以使用 strrchr 获取字符串的“尾部”,从最后一个“_”开始。
If it's only the last integer causing trouble, you can use strrchr to get the "tail" of the string, starting with the last '_'.