merge: Improved pangram algorithm using regular expressions (#906)

* feat: used regex instead of Set

* docs: add js doc

* docs: add comments of workable code

* style: format via standardJs

* docs: add details explanation of pangram regex

* docs: add example

* feat: add two implemetaion of

The first implementation with regex and second via HashSet & add the test code for both

* chore: add QNA format of **Pangram**

* style: format with standardJs

* resolve: removed 'Ans'
This commit is contained in:
Fahim Faisaal
2022-02-28 11:29:09 +06:00
committed by GitHub
parent d466be977e
commit e8de031539
2 changed files with 84 additions and 20 deletions

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@ -1,22 +1,54 @@
/*
Pangram is a sentence that contains all the letters in the alphabet
https://en.wikipedia.org/wiki/Pangram
/**
* What is Pangram?
* Pangram is a sentence that contains all the letters in the alphabet https://en.wikipedia.org/wiki/Pangram
*/
const checkPangram = (string) => {
/**
* @function checkPangramRegex
* @description - This function check pangram with the help of regex pattern
* @param {string} string
* @returns {boolean}
* @example - checkPangramRegex("'The quick brown fox jumps over the lazy dog' is a pangram") => true
* @example - checkPangramRegex('"Waltz, bad nymph, for quick jigs vex." is a pangram') => true
*/
const checkPangramRegex = (string) => {
if (typeof string !== 'string') {
throw new TypeError('The given value is not a string')
}
const frequency = new Set()
for (const letter of string.toLowerCase()) {
if (letter >= 'a' && letter <= 'z') {
frequency.add(letter)
}
}
return frequency.size === 26
/**
* Match all 26 alphabets using regex, with the help of:
* Capturing group - () -> Groups multiple tokens together and creates a capture group for extracting a substring or using a backreference.
* Character set - [a-z] -> Matches a char in the range a to z in case-insensitive for the 'i' flag
* Negative lookahead - (?!) -> Specifies a group that can not match after the main expression (if it matches, the result is discarded).
* Dot - . -> Matches any character except linebreaks. Equivalent to
* Star - * -> Matches 0 or more of the preceding token.
* Numeric reference - \{$n} -> Matches the results of a capture group. E.g. - \1 matches the results of the first capture group & \3 matches the third.
*/
return string.match(/([a-z])(?!.*\1)/gi).length === 26
}
export { checkPangram }
/**
* @function checkPangramSet
* @description - This function detect the pangram sentence by HashSet
* @param {string} string
* @returns {boolean}
*/
const checkPangramSet = (string) => {
if (typeof string !== 'string') {
throw new TypeError('The given value is not a string')
}
const lettersSet = new Set()
for (const letter of string.toUpperCase()) {
if (/[A-Z]/.test(letter)) {
// if the letter is a valid uppercase alphabet then the add method insert the letter to the HashSet
lettersSet.add(letter)
}
}
return lettersSet.size === 26
}
export { checkPangramRegex, checkPangramSet }

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@ -1,33 +1,65 @@
import { checkPangram } from '../CheckPangram'
import { checkPangramRegex, checkPangramSet } from '../CheckPangram'
describe('checkPangram', () => {
describe('Testing checkPangramRegex function', () => {
it('"The quick brown fox jumps over the lazy dog" is a pangram', () => {
expect(
checkPangram('The quick brown fox jumps over the lazy dog')
).toBeTruthy()
checkPangramRegex('The quick brown fox jumps over the lazy dog')
).toBe(true)
})
it('"Waltz, bad nymph, for quick jigs vex." is a pangram', () => {
expect(checkPangram('Waltz, bad nymph, for quick jigs vex.')).toBeTruthy()
expect(checkPangramRegex('Waltz, bad nymph, for quick jigs vex.')).toBe(true)
})
it('"Jived fox nymph grabs quick waltz." is a pangram', () => {
expect(checkPangram('Jived fox nymph grabs quick waltz.')).toBeTruthy()
expect(checkPangramRegex('Jived fox nymph grabs quick waltz.')).toBe(true)
})
it('"My name is Unknown" is NOT a pangram', () => {
expect(checkPangram('My name is Unknown')).toBeFalsy()
expect(checkPangramRegex('My name is Unknown')).toBe(false)
})
it('"The quick brown fox jumps over the la_y dog" is NOT a pangram', () => {
expect(
checkPangram('The quick brown fox jumps over the la_y dog')
).toBeFalsy()
checkPangramRegex('The quick brown fox jumps over the la_y dog')
).toBe(false)
})
it('Throws an error if given param is not a string', () => {
expect(() => {
checkPangram(undefined)
checkPangramRegex(undefined)
}).toThrow('The given value is not a string')
})
})
describe('Testing checkPangramSet function', () => {
it('"The quick brown fox jumps over the lazy dog" is a pangram', () => {
expect(
checkPangramSet('The quick brown fox jumps over the lazy dog')
).toBe(true)
})
it('"Waltz, bad nymph, for quick jigs vex." is a pangram', () => {
expect(checkPangramSet('Waltz, bad nymph, for quick jigs vex.')).toBe(true)
})
it('"Jived fox nymph grabs quick waltz." is a pangram', () => {
expect(checkPangramSet('Jived fox nymph grabs quick waltz.')).toBe(true)
})
it('"My name is Unknown" is NOT a pangram', () => {
expect(checkPangramSet('My name is Unknown')).toBe(false)
})
it('"The quick brown fox jumps over the la_y dog" is NOT a pangram', () => {
expect(
checkPangramSet('The quick brown fox jumps over the la_y dog')
).toBe(false)
})
it('Throws an error if given param is not a string', () => {
expect(() => {
checkPangramSet(undefined)
}).toThrow('The given value is not a string')
})
})