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מודול 5 · שיעור 1 מתוך 417/32 בקורס~8 min
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ערכות תווים: `[abc]`

When a predefined class like \d or \w is not enough, you can define a custom character set with square brackets [...]. Inside the brackets, each character is an alternative: the regex matches one of any of the listed elements.

Code
Pattern: [aeiou]
Sample:  ciao mondo
         ^   ^^  ^^

Each vowel is a match on its own. Brackets match exactly one character (unless quantified): [aeiou]+ matches a contiguous sequence of vowels.

Special characters inside brackets

Inside [...] most meta-characters lose their special meaning:

  • . inside [.] matches a literal dot (no escape needed).
  • *, +, ?, (, ), {, } are literal.
  • \ ] ^ instead remain special and must be escaped or carefully positioned.
Code
Pattern: [.,;:]
Match: any punctuation mark among dot, comma, semicolon, colon.

Special characters inside square brackets

Most regex meta-characters (., *, +, ?, etc.) lose their special meaning inside brackets and are treated as literal characters. Only the dash -, the caret ^ at the start, and the backslash \\ retain operational meanings.

Try it

פעילות גופנית#regex.m5.l1.e1
ניסיונות: 0טוען...

Find every vowel (a, e, i, o, u, including uppercase) in the text, one by one.

טוען עורך...
הצג רמז

Add the uppercase vowels inside the brackets, or use the i flag.

הפתרון זמין לאחר 3 ניסיונות

Review exercise

פעילות גופנית#regex.m5.l1.e2
ניסיונות: 0טוען...

Find punctuation marks: dot, comma, semicolon, colon, exclamation mark, question mark.

טוען עורך...
הצג רמז

Inside [.,;:!?] all characters are literal, no escaping needed.

הפתרון זמין לאחר 3 ניסיונות

Additional challenge

פעילות גופנית#regex.m5.l1.e3
ניסיונות: 0טוען...

Find all Italian accented vowels (`àèéìòù`) in the text.

טוען עורך...
הצג רמז

List the accented letters inside square brackets.

הפתרון זמין לאחר 3 ניסיונות