Regular expressions are used for pattern matching from the beginning.
It can look similar to a wild card but there are quite a big differences.
Regular expressions can be used to much for example email address or IP address and are usually used
among scripts.
So let's check how it looks like here.
They have symbols which are used for regular expression.
Start the differences define dot represents any single character.
So for example more dot K Menchie's bog or for example bar one key next symbol is asterisk and it is
really confusing when you know wildcards meaning of asterisk.
It means that preceding item must match 0 or more times.
So call asterisk now matches.
See how he has because that all it can be match zero times.
This is correct.
Then it also matches goal goal and so on
stat of the line is represented by card.
So card Hello Michie's.
Well I'm starting with Hello similarily end of the line is represented by dollar sign.
So hello dollar sign Michie's line ending with Hello.
Square brackets are the same as for wild cards.
Any one of character Ingo's in square brackets when we use arr. inside square brackets for example file
one Desch the images file one file to Vios three do remember on wild wildcard.
Exclamation mark inside brackets.
Here it is the same situation except the one offering.
Instead of exclamation mark we are using.
Correct and it means any character except those enclosed in brackets.
So file an inside square brackets get 0 1 2 3 4 5 6 7 Menchie's file 8 and file 9 next symbol is a question
mark.
It means that the preceding item must match 1 or 0 times so call question mark hour would match.
Core core but not core.
With W.
Days go to mention that regular expression are not so easy in general and many people are learning them
more than month.
So don't be afraid of them.
Once we will practice it it will be much easier.
If preceding item must match one or more times we should use symbol plus five.
One plus then match file 1 file 11 file 108 11 but not file number inside curly brackets it means that
preceding item must match end times.
That means if we have a range 0 2 9 and in curly brackets number three it would match any three digit
number as one hundred eleven 256 and so on.
And very similar to use in the curly bracket number with comma.
Which means that preceding item should match the minimum number of times.
So in our example it would match any serie or more digit number when we specify to number in the curly
brackets.
We are specifying minimum and maximum number of times the preceding item should match.
So if we specify a range 0 2 9 and inside curly brackets we have numbers 1 and 3 Demetri's or one two
or three digit number.
Last symbol here is backslash.
We are using it as an escape character.
It will escape any of the special character to.
Ignore the meaning of them.
Of course we can use character classes and then use it.
Don't forget to wrap it inside square brackets.
That means that you would have Debro square brackets.
Now let's check how to override the rejects in the script.
If you want to know if string matches some rec X we are using the following double square brackets and
inside some string variable then equal sign for Dubai Guilder and then Reg's a variable.
And don't forget on spaces here.
Now we can see the x example has also some cool feature for matching red X for example beshe rematch
0 matches part of the string.
Which match Reg x 4 part of string which matches HOERR I guess you can also use a variable image and
beshe rematch.
One match is part of the string which is represented as everything inside the exits in close parentheses.
So how do you feel now.
I think the best would be to write some script to see it in action and ensure that there is no magic
at all.