[英]How to remove non-alphanumeric characters?
I need to remove all characters from a string which aren't in az AZ 0-9
set or are not spaces.我需要从不在
az AZ 0-9
集中或不是空格的字符串中删除所有字符。
Does anyone have a function to do this?有没有人有 function 可以做到这一点?
Sounds like you almost knew what you wanted to do already, you basically defined it as a regex.听起来您几乎已经知道自己想要做什么,您基本上将其定义为正则表达式。
preg_replace("/[^A-Za-z0-9 ]/", '', $string);
For unicode characters, it is:对于 unicode 字符,它是:
preg_replace("/[^[:alnum:][:space:]]/u", '', $string);
Regular expression is your answer.正则表达式是你的答案。
$str = preg_replace('/[^a-z\d ]/i', '', $str);
i
stands for case insensitive. i
代表不区分大小写。^
means, does not start with. ^
表示,不以开头。\d
matches any digit. \d
匹配任何数字。az
matches all characters between a
and z
. az
匹配a
和z
之间的所有字符。 Because of the i
parameter you don't have to specify az
and AZ
.i
参数,您不必指定az
和AZ
。\d
there is a space, so spaces are allowed in this regex. \d
之后有一个空格,因此此正则表达式中允许有空格。 here's a really simple regex for that:这是一个非常简单的正则表达式:
\W|_
and used as you need it (with a forward /
slash delimiter).并根据需要使用
/
使用正斜杠分隔符)。
preg_replace("/\W|_/", '', $string);
Test it here with this great tool that explains what the regex is doing:使用这个解释正则表达式在做什么的好工具在这里测试它:
[\W_]+
$string = preg_replace("/[\W_]+/u", '', $string);
It select all not AZ, az, 0-9 and delete it.它 select 都不是 AZ, az, 0-9 并删除它。
See example here: https://regexr.com/3h1rj请参阅此处的示例: https://regexr.com/3h1rj
If you need to support other languages, instead of the typical AZ, you can use the following:如果您需要支持其他语言,而不是典型的 AZ,您可以使用以下内容:
preg_replace('/[^\p{L}\p{N} ]+/', '', $string);
[^\p{L}\p{N} ]
defines a negated (It will match a character that is not defined) character class of: [^\p{L}\p{N} ]
定义了一个否定(它将匹配一个未定义的字符)字符 class:
\p{L}
: a letter from any language. \p{L}
:任何语言的字母。\p{N}
: a numeric character in any script. \p{N}
:任何脚本中的数字字符。
: a space character. +
greedily matches the character class between 1 and unlimited times. +
贪婪地匹配字符 class 1 到无限次。 This will preserve letters and numbers from other languages and scripts as well as AZ:这将保留来自其他语言和脚本以及 AZ 的字母和数字:
preg_replace('/[^\p{L}\p{N} ]+/', '', 'hello-world'); // helloworld
preg_replace('/[^\p{L}\p{N} ]+/', '', 'abc@~#123-+=öäå'); // abc123öäå
preg_replace('/[^\p{L}\p{N} ]+/', '', '你好世界!@£$%^&*()'); // 你好世界
Note: This is a very old, but still relevant question.注意:这是一个非常古老但仍然相关的问题。 I am answering purely to provide supplementary information that may be useful to future visitors.
我回答纯粹是为了提供可能对未来访问者有用的补充信息。
preg_replace("/\W+/", '', $string)
You can test it here: http://regexr.com/你可以在这里测试它: http://regexr.com/
I was looking for the answer too and my intention was to clean every non-alpha and there shouldn't have more than one space.我也在寻找答案,我的意图是清理每一个非 alpha 并且不应该有超过一个空间。
So, I modified Alex's answer to this, and this is working for me preg_replace('/[^az|\s+]+/i', ' ', $name)
所以,我修改了亚历克斯对此的回答,这对我
preg_replace('/[^az|\s+]+/i', ' ', $name)
The regex above turned sy8ed sirajul7_islam
to sy ed sirajul islam
上面的正则表达式将
sy8ed sirajul7_islam
了sy ed sirajul islam
Explanation: regex will check NOT ANY from a to z in case insensitive way or more than one white spaces, and it will be converted to a single space.说明:正则表达式将检查NOT ANY from a to z 以不区分大小写或多个空格,并将其转换为单个空格。
You can split the string into characters and filter it.您可以将字符串拆分为字符并对其进行过滤。
<?php
function filter_alphanum($string) {
$characters = str_split($string);
$alphaNumeric = array_filter($characters,"ctype_alnum");
return join($alphaNumeric);
}
$res = filter_alphanum("a!bc!#123");
print_r($res); // abc123
?>
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