Question
What is the regex pattern to replace two or more consecutive identical characters in a string with only one character?
/(.)\1+/g
Answer
Replacing consecutive characters in a string using regular expressions is a powerful technique often utilized in text processing. The regex pattern can be designed to identify duplicates and replace them with a single instance of the character, enhancing data consistency and readability.
const inputString = 'aaabbbcccd';
const outputString = inputString.replace(/(.)\1+/g, '$1');
console.log(outputString); // Output: 'abcd'
Causes
- You may have mistakenly added multiple characters while typing.
- Data entry errors could lead to multiple identical characters appearing in strings.
Solutions
- Use a regex pattern that matches consecutive identical characters.
- Apply a replacement function to substitute these duplicates with a single character.
Common Mistakes
Mistake: Using the wrong regex pattern that doesn't capture duplicates.
Solution: Ensure you use (.)\1+ to match consecutive identical characters.
Mistake: Forgetting to include the global flag 'g' which limits the replacement to the first occurrence only.
Solution: Always include 'g' at the end of your regex to ensure all instances are replaced.
Helpers
- regular expressions
- replace consecutive characters
- regex pattern
- string manipulation
- JavaScript string replacement