查找“."用string.find() [英] Finding '.' with string.find()

问题描述

我试图做一个简单的字符串操作:获取文件名，不带扩展名.只是，string.find()似乎存在点问题:

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

并且仅带点:

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

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()默认情况下不会在字符串中找到字符串，而是找到

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，可以表示任何字符.

要真正找到字符串.，需要使用百分号%.

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)，它允许您传入true作为最后一个参数，并搜索纯字符串.那将使您发表声明；

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

这篇关于查找“."用string.find()的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！