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Summary: Learn how to craft a regular expression (regex) to match numbers between 1 and 100, including the syntax and logic behind creating effective regex patterns.
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How to Use Regex to Match Numbers Between 1 and 100

Regular expressions, or regex, are powerful tools used for pattern matching and text manipulation. They can be particularly useful for identifying numerical ranges within text, such as numbers between 1 and 100. In this guide, we will guide you through the process of crafting a regex pattern to match numbers in this specific range.

Understanding the Problem

To effectively match numbers between 1 and 100, we need to consider that the range includes:

Single-digit numbers (1-9)

Double-digit numbers (10-99)

The number 100

This means our regex pattern should account for each of these cases.

Building the Regex Pattern

Step-by-Step Breakdown

Single-Digit Numbers (1-9):
These are straightforward since they are simply digits from 1 to 9.

[[See Video to Reveal this Text or Code Snippet]]

Double-Digit Numbers (10-99):
These involve a tens place digit from 1-9, followed by any digit from 0-9.

[[See Video to Reveal this Text or Code Snippet]]

The Number 100:
This is a static pattern since it is a fixed number.

[[See Video to Reveal this Text or Code Snippet]]

Combining the Patterns

To combine these three patterns into a single regex, we use the alternation operator (|), which allows us to match any one of the specified patterns.

[[See Video to Reveal this Text or Code Snippet]]

However, this pattern can be optimized further for better readability and efficiency:

[[See Video to Reveal this Text or Code Snippet]]

Here's a breakdown of this optimized pattern:

\b: Word boundary, ensures matching whole numbers only

100: Matches the number 100 specifically

[1-9]?: Matches 0 or 1 occurrence of digits 1-9 (for numbers 1-9)

[0-9]: Matches any digit (for numbers 0-99)

Testing the Regex Pattern

It's essential to test our regex pattern to ensure it accurately matches numbers between 1 and 100. You can use various regex testing tools available online or integrate this pattern into your code.

Examples:

The pattern should match: 1, 25, 99, 100.

The pattern should not match: 0, 101, 123, a50.

Conclusion

Crafting a regex pattern to match numbers between 1 and 100 involves understanding how to target both single and double-digit numbers as well as the specific number 100. By using the principles and patterns outlined in this post, you can create an efficient and effective regular expression for your specific needs.

Regex offers versatility and power in text processing, making it a valuable skill for anyone working with textual data. Happy pattern matching!