Vigenère cipher: Difference between revisions

=={{header|TypeScript}}==

<lang JavaScript>class Vigenere {

key: string

/** Create new cipher based on key */

constructor(key: string) {

this.key = Vigenere.formatText(key)

}

/** Enrypt a given text using key */

encrypt(plainText: string): string {

return Array.prototype.map.call(Vigenere.formatText(plainText), (letter: string, index: number): string => {

return String.fromCharCode((letter.charCodeAt(0) + this.key.charCodeAt(index % this.key.length) - 130) % 26 + 65)

}).join('')

}

/** Decrypt ciphertext based on key */

decrypt(cipherText: string): string {

return Array.prototype.map.call(Vigenere.formatText(cipherText), (letter: string, index: number): string => {

return String.fromCharCode((letter.charCodeAt(0) - this.key.charCodeAt(index % this.key.length) + 26) % 26 + 65)

}).join('')

}

/** Converts to uppercase and removes non characters */

private static formatText(text: string): string {

return text.toUpperCase().replace(/[^A-Z]/g, "")

}

}

/** Example usage */

(() => {

let original: string = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book."

console.log(`Original: ${original}`)

let vig: Vigenere = new Vigenere("vigenere")

let encoded: string = vig.encrypt(original)

console.log(`After encryption: ${encoded}`)

let back: string = vig.decrypt(encoded)

console.log(`After decryption: ${back}`)

})()

<\lang>