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You have completed Introduction to Regular Expressions!
You have completed Introduction to Regular Expressions!
Preview
Learn match ranges of characters such as a-z, A-Z or 0-9.
Practice
Copy each set of test strings into regex101. Using what you've learned so far, create a regular expression that will match all of the strings in the set.
1 )
bat
cat
data
eat
fast
2 )
1 a
2 a
3 a
4 a
5 a
8 a
9 b
3 )
8345 Gable
7238 Gable
2349 Table
8475 Cable
0994 Fable
1047 Zable
4 )
4849
4472
4901
40502
43470
40496
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You can also match a range of letters,
like A through Z, or
0:00
a range of numbers,
like 0 through 9, in character sets.
0:05
Let's say, instead of the first set that
matches just these three characters,
0:10
you want to match any
letter in the alphabet.
0:15
This can be done by replacing
the contents of the brackets.
0:18
We'll set A-Z.
0:25
This hyphen tells the parser to include
all letters in the range from A to Z.
0:29
You can see below that only one
of the strings is highlighted.
0:36
That's because we've only
specified uppercase letters.
0:39
To include all lowercase letters,
0:43
you can put another range right
next to the first, lowercase a-z.
0:46
So ranges are put right next to
each other in the square brackets.
0:53
Notice all the strings
are highlighted again.
0:58
That's because the ranges we
just entered include the Ts and
1:00
the Js that these strings start with.
1:05
I'll just change one of these Ts to a Z.
1:09
It still matches.
1:13
Now I'll change it to a capital S.
1:16
Cool, it still matches.
1:18
I'm going to change it back to the t.
1:21
I also want to show you that you
can use numerals in the same way.
1:23
I'll just create a new character set
at the beginning of the expression.
1:28
In square brackets, followed by a space,
I'm going to add 0 through 7.
1:34
All of our tests are unmatched now
because the parser is looking for
1:41
the string to start with
a numeral between 0 and 7.
1:46
I'll type a 2 on the second line, followed
by a space, and it's matched again.
1:50
I'll replace it with a 9,
and it's unmatched.
1:59
Note that I can still enter individual
characters I want to match into the set.
2:04
For example, let's say that I
want to match the letter a.
2:09
I can type that into the set and
then use it in our first line.
2:15
It matches.
2:21
Try some of the exercises in
the teachers notes for more practice.
2:23
Next, we'll look at a more concise
way to express common character sets.
2:28
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