What is the regex for repeated words?

The regex pattern for repeated words is `\b(\w+)\s+\1\b`. This pattern validates detects consecutive duplicate words (e.g. "the the").

How do I use this regex in JavaScript?

In JavaScript, create the regex with `const regex = /\b(\w+)\s+\1\b/;` and test with `regex.test(yourValue)`. It returns `true` if the value matches.

How do I use this regex in Python?

In Python, use `import re; re.match(r'\b(\w+)\s+\1\b', value)`. The raw string prefix (`r`) prevents Python from interpreting backslashes as escape characters.

Is this regex case-sensitive?

By default, yes. To make it case-insensitive, add the `i` flag in JavaScript (`/\b(\w+)\s+\1\b/i`) or use `re.IGNORECASE` in Python.

Regex for Repeated Words

Regex Pattern

\b(\w+)\s+\1\b

Detects consecutive duplicate words (e.g. "the the")

Quick Answer

The regex pattern for repeated words is `\b(\w+)\s+\1\b`. Detects consecutive duplicate words (e.g. "the the"). This works in JavaScript, Python, Ruby, PHP, Java, and most regex engines that support PCRE syntax.

Test Examples

Input	Result
the the quick fox	✓ Matches
is is broken	✓ Matches
very very good	✓ Matches
the quick fox	✗ No match
no repeats here	✗ No match
their there	✗ No match

Code Examples

javascript

const regex = /\b(\w+)\s+\1\b/;
const isValid = regex.test(value);

python

import re
pattern = r'\b(\w+)\s+\1\b'
if re.match(pattern, value):
    print("valid")

ruby

pattern = /\b(\w+)\s+\1\b/
if value =~ pattern
  puts "valid"
end

php

if (preg_match('/\b(\w+)\s+\1\b/', $value)) {
    echo "valid";
}

java

String pattern = "\\b(\\w+)\\s+\\1\\b";
boolean isValid = value.matches(pattern);

Frequently Asked Questions

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