如何从PHP中的字符串获取大写字母序列？

Question

In PHP , how do I get only upper case sequences from the string?

For example, how can I get from:

abcDEF GHi jklm

only:

DEF GH

Answer 1

To find matches:

preg_match('/[A-Z]+/', $input, $matches);

To remove all "wrong" stuff:

$output = preg_replace('/[^A-Z ]/', '', $input);

Answer 2

使用此正则表达式[AZ]+

Answer 3

A string of upper case letters can be matched with [AZ]+

However, if you specifically want words that are only upper case, then you need to add a word boundary marker to each end of the expression. This is \\b .

So your expression would look like this:

/\b[A-Z]+\b/

Hope that helps.