regular expression to match words with space or no space

Question

我正在尝试找到与正则表达式匹配的PHP正则表达式，例如带空格的“ Hello World”，还匹配不带空格的“ HelloWorld”。

Answer 1

You could use:

/^Hello ?World$/

Or you don't care the number of spaces:

/^Hello *World$/

Or it could also be blank chars like tab, then use \\s instead a space.

Answer 2

Generally that would be:

/[a-zA-Z ]+/

If you want numbers, too:

/[a-zA-Z0-9 ]+/

You would need to set some sort of boundary. If the string just contains this, you can use start and end delimiters:

/^[a-zA-Z0-9 ]+$/