is-palindrome

Checks if a string is a palindrome with a grouping feature not seen in other palindrome checkers.

Node Repository

https://www.npmjs.com/package/@pelevesque/is-palindrome

Installation

npm install @pelevesque/is-palindrome

Tests

Command	Description
npm test or npm run test	All Tests Below
npm run cover	Standard Style
npm run standard	Coverage
npm run unit	Unit Tests

Usage

Parameters

str                    (required)
groupBy                (optional) default = 1
pivotMustBePalindromic (optional) default = false

Examples

const isPalindrome = require('@pelevesque/is-palindrome')

// works with traditional palindromes
isPalindrome('')      // false
isPalindrome('12345') // false
isPalindrome('a')     // true
isPalindrome('1221')  // true
isPalindrome('12321') // true

// a groupBy parameter can be used to group elements
const groupBy = 2
isPalindrome('abba',  groupBy) // false
isPalindrome('abab',  groupBy) // true
isPalindrome('abcba', groupBy) // true

// pivots do not have to be palindromic by default
// they exist when a center point is smaller than groupBy * 2
const groupBy = 4
isPalindrome('abcd!@#$123!@#$abcd',   groupBy) // true
isPalindrome('abcd!@#$1234!@#$abcd',  groupBy) // true
isPalindrome('abcd!@#$12345!@#$abcd', groupBy) // true
isPalindrome('abcd!@#$12321!@#$abcd', groupBy) // true

// the pivotMustBePalindromic flag can be used to force palindromic pivots
const groupBy = 4
const pivotMustBePalindromic = true
isPalindrome('abcd!@#$12345!@#$abcd', groupBy, pivotMustBePalindromic) // false
isPalindrome('abcd!@#$12321!@#$abcd', groupBy, pivotMustBePalindromic) // true