Question

我知道这个问题很多次，但我找不到任何解决方案来进行具体验证。

我想验证电子邮件地址中的用户名，只接受字母，数字，下划线和DOT和NO破折号（ - ）或任何特殊字符，例如！＃％＆amp; *（）

像这样：aaa @ aa.com，d123 @ ad.com，22_dd @ dd.com，dfd.df @ ds.com

不是这样的：ss-ee @ sd.com，fsd！@ atd.com，11-ee @ sd.com

我做了什么：

if (!preg_match("/[a-zA-Z0-9]+@[a-zA-Z0-9]+.[a-zA-Z]+/", $email)) return("Invalid email address");

但它接受破折号。

Answer 1

你可以这样做：

if (!preg_match('/^(?!.*?\.\.)[\w.]+@(?:[a-zA-Z0-9-]+\.)+[a-zA-Z]+$/', $email)) 
    return("Invalid email address");

Answer 2

要防止连续2个点（.）使用negative lookahead (?!.*?\.\.)

if (!preg_match('/^(?!.*?\.\.)[a-z0-9_.]+@[a-z0-9.-]+\.[a-z]+$/im', $email))
    return("Invalid email address");

说明：

^             # Assert position at the beginning of a line (at beginning of the string or after a line break character) (line feed)
(?!           # Assert that it is impossible to match the regex below starting at this position (negative lookahead)
   .             # Match any single character that is NOT a line break character (line feed)
      *?            # Between zero and unlimited times, as few times as possible, expanding as needed (lazy)
   \.            # Match the character “.” literally
   \.            # Match the character “.” literally
)
[a-z0-9_.]    # Match a single character present in the list below
                 # A character in the range between “a” and “z” (case insensitive)
                 # A character in the range between “0” and “9”
                 # A single character from the list “_.”
   +             # Between one and unlimited times, as many times as possible, giving back as needed (greedy)
@             # Match the character “@” literally
[A-Z0-9.-]    # Match a single character present in the list below
                 # A character in the range between “A” and “Z” (case insensitive)
                 # A character in the range between “0” and “9”
                 # The literal character “.”
                 # The literal character “-”
   +             # Between one and unlimited times, as many times as possible, giving back as needed (greedy)
\.            # Match the character “.” literally
[A-Z]         # Match a single character in the range between “A” and “Z” (case insensitive)
   +             # Between one and unlimited times, as many times as possible, giving back as needed (greedy)
\$             # Assert position at the end of a line (at the end of the string or before a line break character) (line feed)

Answer 3

您可以使用以下正则表达式，这也会阻止用户名中的2个连续点：

^(?!.*\.\..*@)[a-zA-Z0-9_.]+@\S+\.[a-zA-Z]+$

请参阅demo here。

<强>详情

^ - 字符串开头
(?!.*\.\..*@) - 如果仅在用户名部分中有两个连续的点，则表示匹配失败的否定前瞻
[a-zA-Z0-9_.]+ - 一个或多个ASCII字母，数字或_或.
@ - @
\S+ - 1 +非空白字符
\. - 一个点
[a-zA-Z]+ - 一个或多个ASCII字母
$ - 字符串结束。

示例代码：

$re = "/^(?!.*\\.\\..*@)[a-zA-Z0-9_.]+@\\S+\\.[a-zA-Z]+$/m"; 
$str = "334345jtjert..j547j@ds.com\n334345jtjert.j547j@ds.com\nss-ee@sd.com\nfsd!@asd.com\n11-ee@sd.com"; 
preg_match($re, $str, $matches);

Answer 4

您可以使用：

[\\w\\-\\+\\&\\*]+(?:\\.[\\w\\-\\_\\+\\&\\*]+)*@(?:[\\w-]+\\.)+[a-zA-Z]{2,7}

通过用户名验证进行电子邮件验证，仅接受字母，数字，下划线和DOT

4 个答案: