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Modul 2 · Pelajaran 2 dari 46/32 dalam kursus~10 min
Pelajaran modul (2/4)

Besaran pastinya `{n,m}`

When you need precise control over the number of repetitions, you use the brace notation {n,m}:

SyntaxMeaning
\d{4}Exactly 4 digits
\d{2,4}From 2 to 4 digits
\d{3,}At least 3 digits

{n} is equivalent to {n,n}. {n,} has no maximum. {,m} is not supported in JavaScript (you must write {0,m}).

Code
Pattern: \d{4}
Sample:  Anni: 2020, 2024, 1999, errore 99.
               ^^^^  ^^^^  ^^^^

{4} stops the match at exactly four digits: 99 does not match because it has only two. 12345 would match the first four digits (1234), not the whole number.

Open intervals and repetition limits

The curly brace notation is flexible: {n} indicates exact repetition, {n,m} a closed range from n to m, while {n,} leaves the upper limit open ("at least n times"). The engine processes these efficiently, reducing the ambiguities of generic quantifiers.

Try it

Latihan#regex.m2.l2.e1
Upaya: 0Memuat…

Find every 4-digit year in the text (e.g. `2024`, but not `99`).

Memuat editor…
Tunjukkan petunjuk

Exactly 4 digits: use the {4} notation on the \\d class.

Solusi tersedia setelah 3 upaya

Review exercise

Latihan#regex.m2.l2.e2
Upaya: 0Memuat…

Find every number made of 2, 3 or 4 digits (excluding 1-digit numbers and numbers 5+ digits long).

Memuat editor…
Tunjukkan petunjuk

Range {2,4}: minimum 2, maximum 4 digits. Without anchors it will also match the first 4 digits of 12345.

Solusi tersedia setelah 3 upaya

Additional challenge

Latihan#regex.m2.l2.e3
Upaya: 0Memuat…

Find phone numbers in the format `XXX-XXXX` (exactly 3 digits, dash, exactly 4 digits).

Memuat editor…
Tunjukkan petunjuk

Use curly braces {3} and {4} applied to the \d class.

Solusi tersedia setelah 3 upaya