Lua操作字符串的5个代码片段分享

1.匹配字符串中的数字、字母和下划线

str = "hello_+asdf2312+887441a+asdf"

table = {}

string.gsub(str, "([%w_]+)",

function(w)
table.insert(table,w)
end

end

2.替换字符串中的指定字符

str = "hello,john"

s = string.gsub(str, "john", "james")

s ==>"hello,james"

3.判断字符串中是否有目标字串

str = "hello,john"

start, end = string.find(str, "hello")

start ==>1

end ==>5

4.从文件的绝对路径中获取到文件名

fn_flag = string.find(filename, "")

if fn_flag then
dest_filename = string.match(filename, ".+([^]*%.%w+)$")

end

fn_flag = string.find(filename, "/")
if fn_flag then
dest_filename = string.match(filename, ".+/([^/]*%.%w+)$")

end

5.去掉字符串中括号内的内容，并去掉收尾的空格

str = " helloa,ni hao (asdfasdf) "

newstr = string.gsub(str,"%b()","")

newstr = string.gsub(newstr, "^%s*(.-)%s*$", "%1")
print(newstr)---->helloa,ni hao