寻找“."使用 string.find() [英] Finding '.' with string.find()

问题描述

我正在尝试进行简单的字符串操作:获取文件名，不带扩展名.只是，string.find() 似乎有点问题:

I'm trying to make a simple string manipulation: getting the a file's name, without the extension. Only, string.find() seem to have an issue with dots:

s = 'crate.png'
i, j = string.find(s, '.')
print(i, j) --> 1 1

而且只有点:

s = 'crate.png'
i, j = string.find(s, 'p')
print(i, j) --> 7 7

这是一个错误，还是我做错了什么?

Is that a bug, or am I doing something wrong?

推荐答案

string.find()，默认不查找字符串中的字符串，而是查找 模式 字符串.可以在链接中找到更完整的信息，但这里是相关部分；

string.find(), by default, does not find strings in strings, it finds patterns in strings. More complete info can be found at the link, but here is the relevant part;

'.'表示通配符，可以表示任意字符.

The '.' represents a wildcard character, which can represent any character.

要真正找到字符串.，句点需要用百分号转义，%.

To actually find the string ., the period needs to be escaped with a percent sign, %.

或者，您可以传入一些额外的参数，find(pattern, init, plain) 允许您传入 true 作为最后一个参数并进行搜索对于普通字符串.那会让你的陈述；

Alternately, you can pass in some extra arguments, find(pattern, init, plain) which allows you to pass in true as a last argument and search for plain strings. That would make your statement;

> i, j = string.find(s, '.', 1, true)   -- plain search starting at character 1
> print(i, j) 
6 6

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