Regexp which matches nothing?

Ruby
1

How i can construct regexp, which will always matches nothing?

For example:

“xxxxxxx”.match /my_special_regexp/
=> should be ALWAYS nil

2

Joao S. wrote:

How i can construct regexp, which will always matches nothing?

For example:

“xxxxxxx”.match /my_special_regexp/
=> should be ALWAYS nil

How about:

re = /$a^/

3

Why do you want to have a such regex ?

Anyway, it seems that /^$a/ will never match with any string.

“a”.match /^$a/
=> nil
“”.match /^$a/
=> nil
"a ".match /^$a/
=> nil

4

7stud – wrote:

Joao S. wrote:

How i can construct regexp, which will always matches nothing?

For example:

“xxxxxxx”.match /my_special_regexp/
=> should be ALWAYS nil

How about:

re = /$a^/

I guess that could be made even simpler:

re = /a^/

5

Joao S. wrote:

How i can construct regexp, which will always matches nothing?

For example:

“xxxxxxx”.match /my_special_regexp/
=> should be ALWAYS nil
not sure, but something that should always be nil … what about the
constant ‘nil’ :wink:

6

Joao S. wrote:

How i can construct regexp, which will always matches nothing?

For example:

“xxxxxxx”.match /my_special_regexp/
=> should be ALWAYS nil

Just out of curiosity: Why do you use a method call, when you expect a
constant?

7

7stud – wrote:

7stud – wrote:

Joao S. wrote:

How i can construct regexp, which will always matches nothing?

For example:

“xxxxxxx”.match /my_special_regexp/
=> should be ALWAYS nil

How about:

re = /$a^/

I guess that could be made even simpler:

re = /a^/

…and probably more efficient:

re = /a\A/