[z|f]ood  # 会意外匹配 "|ood"
(z|f)ood   # 正确匹配 "zood" 或 "food" 或 “|ood”

	   // 断言（提取价格数字但不包含货币符号）
	   "Price: $100".match(/(?

//heeeeellll ---> // heeeeellll
#heeeeellll ---> # heeeeellll  
(?

#查找：functions(w+)((.*))
#替换：const $1 = ($2)  => 

结果：
function screenCheck()
const screenCheck = ()  =>

查找：([w|.]+)
替换：$2 as $1

结果：
controller as FunctionController
controller

std::cmatch m;
auto ret = std::regex_match("value", m, std::regex("(.*)"));
if (ret)
{
	std::cout value
16
0

valuevalue
xml xml
value value
xml xml
-------------------------------

std::cmatch m;
auto ret = std::regex_match("123value456", m, std::regex("(.*)"));
if (ret)
{
	for (auto& elem : m)
		std::cout value
xml
value
xml

prefix:123
suffix:456
-------------------------------

// 注意：如果有多个符合的内容
std::regex reg("(.*)(.*)>");
std::string content("123value456centerhahahawindowthe end");
std::smatch m;
auto pos = content.cbegin();
auto end = content.cend();
for (; std::regex_search(pos, end, m, reg); pos = m.suffix().first)
{
	std::cout value
xml
value
xml
----------------
center
widget
center
widget
----------------
window
vertical
window
vertical
-------------------------------

string str = "Hello_2018!";	

regex pattern("Hello");	
cout 

var str = "aaabbbcccaaabbbccc";

// match
var res = str.match(/aaa/); // 没有使用g选项
输出：[ 'aaa', index: 0, input: 'aaabbbcccaaabbbccc' ]

var res = str.match(/aaa/g); // g(全局匹配) 使用g选项，全局匹配
输出：[ 'aaa', 'aaa' ]

// exec
var res =/aaa/.exec(str);
输出：[ 'aaa', index: 0, input: 'aaabbbcccaaabbbccc' ]

var res =/aaa/g.exec(str);
输出：[ 'aaa', index: 0, input: 'aaabbbcccaaabbbccc' ]

var res = /ccc([0-9]+)aaa/.exec("aaabbbccc1234aaabbbcccaaabbbccc5678aaabbbccc");
输出：[ 'ccc1234aaa', '1234', index: 6, input: 'aaabbbccc1234aaabbbccc' ]

var res = /ccc([0-9]+)aaa/g.exec("aaabbbccc1234aaabbbcccaaabbbccc5678aaabbbccc");
"ttt.md".match(/(.*).md/)[1]; //返回匹配数组

输出：[ 'ccc1234aaa', '1234', index: 6, input: 'aaabbbccc1234aaabbbcccaaabbbccc5678aaabbbccc' ][ 'ccc5678aaa', '5678', index: 28, input: 'aaabbbccc1234aaabbbcccaaabbbccc5678aaabbbccc' ]

/.*.md$/g.exec("ttt.md")[1]; //返回匹配数组

// search
var res = "aaabbbcccaaabbbccc".search(/ccc/)
输出： 6

var res = "aaabbbcccaaabbbccc".replace(/aaa/, '111′);
输出： 111bbbcccaaabbbccc

// split
var res = "aaa,bbb,ccc".split(/,/)
输出： [ 'aaa', 'bbb', 'ccc' ]
var res = "aaa,bbb:ccc@ddd#eee".split(/[,:@#]/)
输出： [ 'aaa', 'bbb', 'ccc', 'ddd', 'eee' ]
var res = "aaa,bbb:ccc@ddd#eee".split(/[,:@#]/,3)
输出： [ 'aaa', 'bbb', 'ccc' ]

import re

# 1. 邮箱验证
emails = ["test@example.com", "invalid@.com", "name@domain.org"]
pattern = r'^[w.-]+@[w.-]+.[a-zA-Z]{2,6}$'
for email in emails:
    if re.match(pattern, email):
        print(f"✅ 有效邮箱: {email}")
    else:
        print(f"❌ 无效邮箱: {email}")

# 2. 提取日期信息
text = "会议时间: 2023-08-15, 截止日期: 2024-01-20"
dates = re.findall(r'(d{4})-(d{2})-(d{2})', text)
for year, month, day in dates:
    print(f"📅 日期: {year}年{month}月{day}日")

# 3. 替换敏感词
content = "这个价格是500元，但VIP价格是400元"
sanitized = re.sub(r'VIP价格', '***', content)
print(f"🔒 脱敏内容: {sanitized}")

# 4. 分割复杂字符串
data = "Alice:30;Bob:25;Charlie:28"
users = re.split(r'[;:]', data)
print("👥 用户数据:", users)

# 5. 提取HTML标签内容
html = "
标题
正文内容
"
tags = re.findall(r'(.*?)1>', html)
for tag, content in tags:
    print(f"🏷️ {tag}标签内容: {content}")

# 6. 密码强度验证
passwords = ["Pass123!", "weak", "StrongPwd#2023"]
for pwd in passwords:
    if re.match(r'^(?=.*[A-Z])(?=.*[a-z])(?=.*d)(?=.*[!@#$%^&*]).{8,}$', pwd):
        print(f"🔐 强密码: {pwd}")
    else:
        print(f"⚠️ 弱密码: {pwd}")

# 7. 提取中文内容
text = "Python3.8发布 2020年10月，支持中文变量名=很棒"
chinese = re.findall(r'[u4e00-u9fa5]+', text)
print("🇨🇳 中文内容:", chinese)

# 8. 匹配IP地址
ips = ["192.168.1.1", "256.0.0.1", "127.0.0.1"]
pattern = r'^((25[0-5]|2[0-4]d|1d{2}|[1-9]?d).){3}(25[0-5]|2[0-4]d|1d{2}|[1-9]?d)$'
for ip in ips:
    if re.match(pattern, ip):
        print(f"🌐 有效IP: {ip}")
    else:
        print(f"🚫 无效IP: {ip}")

# 9. 多行模式匹配
text = """标题
第一行
最后一行"""
match = re.search(r'^最后一行$', text, re.MULTILINE)
if match:
    print(f"📝 找到结尾行: '{match.group()}'")

# 10. 预编译正则提高性能
pattern = re.compile(r'bw{4}b')  # 匹配4字母单词
text = "This is sample text with some four letter words"
matches = pattern.findall(text)
print("🔤 4字母单词:", matches)