Skip to content

Added a new validator for checking if string is a palindrome #2326

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions README.md
Original file line number Diff line number Diff line change
Expand Up @@ -156,6 +156,7 @@ Validator | Description
**isMultibyte(str)** | check if the string contains one or more multibyte chars.
**isNumeric(str [, options])** | check if the string contains only numbers.<br/><br/>`options` is an object which defaults to `{ no_symbols: false }` it also has `locale` as an option. If `no_symbols` is true, the validator will reject numeric strings that feature a symbol (e.g. `+`, `-`, or `.`).<br/><br/>`locale` determines the decimal separator and is one of `['ar', 'ar-AE', 'ar-BH', 'ar-DZ', 'ar-EG', 'ar-IQ', 'ar-JO', 'ar-KW', 'ar-LB', 'ar-LY', 'ar-MA', 'ar-QA', 'ar-QM', 'ar-SA', 'ar-SD', 'ar-SY', 'ar-TN', 'ar-YE', 'bg-BG', 'cs-CZ', 'da-DK', 'de-DE', 'en-AU', 'en-GB', 'en-HK', 'en-IN', 'en-NZ', 'en-US', 'en-ZA', 'en-ZM', 'es-ES', 'fr-FR', 'fr-CA', 'hu-HU', 'it-IT', 'nb-NO', 'nl-NL', 'nn-NO', 'pl-PL', 'pt-BR', 'pt-PT', 'ru-RU', 'sl-SI', 'sr-RS', 'sr-RS@latin', 'sv-SE', 'tr-TR', 'uk-UA']`.
**isOctal(str)** | check if the string is a valid octal number.
**isPalindrome(str)** | check if the string is a valid palindrome(reads the same forwards and backwards).
**isPassportNumber(str, countryCode)** | check if the string is a valid passport number.<br/><br/>`countryCode` is one of `['AM', 'AR', 'AT', 'AU', 'AZ', 'BE', 'BG', 'BY', 'BR', 'CA', 'CH', 'CN', 'CY', 'CZ', 'DE', 'DK', 'DZ', 'EE', 'ES', 'FI', 'FR', 'GB', 'GR', 'HR', 'HU', 'IE', 'IN', 'IR', 'ID', 'IS', 'IT', 'JM', 'JP', 'KR', 'KZ', 'LI', 'LT', 'LU', 'LV', 'LY', 'MT', 'MX', 'MY', 'MZ', 'NL', 'NZ', 'PH', 'PK', 'PL', 'PT', 'RO', 'RU', 'SE', 'SL', 'SK', 'TH', 'TR', 'UA', 'US', 'ZA']`.
**isPort(str)** | check if the string is a valid port number.
**isPostalCode(str, locale)** | check if the string is a postal code.<br/><br/>`locale` is one of `['AD', 'AT', 'AU', 'AZ', 'BA', 'BE', 'BG', 'BR', 'BY', 'CA', 'CH', 'CN', 'CZ', 'DE', 'DK', 'DO', 'DZ', 'EE', 'ES', 'FI', 'FR', 'GB', 'GR', 'HR', 'HT', 'HU', 'ID', 'IE', 'IL', 'IN', 'IR', 'IS', 'IT', 'JP', 'KE', 'KR', 'LI', 'LK', 'LT', 'LU', 'LV', 'MG', 'MT', 'MX', 'MY', 'NL', 'NO', 'NP', 'NZ', 'PL', 'PR', 'PT', 'RO', 'RU', 'SA', 'SE', 'SG', 'SI', 'SK', 'TH', 'TN', 'TW', 'UA', 'US', 'ZA', 'ZM']` OR `'any'`. If 'any' is used, function will check if any of the locales match. Locale list is `validator.isPostalCodeLocales`.
Expand Down
17 changes: 17 additions & 0 deletions src/lib/isPalindrome.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
/**
* The `isPalindrome` function checks if a given string is a palindrome.
* @param str - The `str` parameter is a string that represents the input value to check if it is a
* palindrome.
* @returns The function isPalindrome is returning a boolean value. It returns true if the input string
* is a palindrome (reads the same forwards and backwards), and false otherwise.
*/
import assertString from "./util/assertString";

export default function isPalindrome(str) {
assertString(str);
const str0 = str.toLowerCase().replace(/[!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~]/g, '');
const str1 = str0.split(" ").join("").split("").join("");
const str2 = str0.split(" ").join("").split("").reverse().join("");

return str1 === str2;
}