Ranges [a-z] [0-9]

Writing every character in a set would be tedious. Ranges let you specify sequences.

Letter Ranges

[a-z] matches any lowercase letter from a to z.

Notice only lowercase letters match, not capitals, numbers, or symbols.

Common Ranges

Range	Matches
[a-z]	Lowercase letters
[A-Z]	Uppercase letters
[0-9]	Digits
[a-zA-Z]	All letters
[a-zA-Z0-9]	Letters and digits

Combining Ranges

You can combine multiple ranges in one set:

Partial Ranges

You don't have to use the full alphabet:

Combining Ranges with Literals

Grade Matching

Practice Playground

Try matching:

• [A-Z][A-Z][A-Z] - three uppercase letters
• [0-9][0-9][0-9] - three digits
• [A-Z][0-9] - letter followed by digit

Key Takeaways

• [a-z] matches lowercase letters a through z
• [A-Z] matches uppercase letters
• [0-9] matches digits
• Combine ranges: [a-zA-Z0-9]
• Use partial ranges: [a-f] for hex letters