Encrypts or decrypts a given string using the Caesar cipher.
%
) operator and the ternary operator (?
) to calculate the correct encryption/decryption key....
) and Array.prototype.map()
to iterate over the letters of the given string.String.prototype.charCodeAt()
and String.fromCharCode()
to convert each letter appropriately, ignoring special characters, spaces etc.Array.prototype.join()
to combine all the letters into a string.true
to the last parameter, decrypt
, to decrypt an encrypted string.const caesarCipher = (str, shift, decrypt = false) => {
const s = decrypt ? (26 - shift) % 26 : shift;
const n = s > 0 ? s : 26 + (s % 26);
return [...str]
.map((l, i) => {
const c = str.charCodeAt(i);
if (c >= 65 && c <= 90)
return String.fromCharCode(((c - 65 + n) % 26) + 65);
if (c >= 97 && c <= 122)
return String.fromCharCode(((c - 97 + n) % 26) + 97);
return l;
})
.join('');
};
caesarCipher('Hello World!', -3); // 'Ebiil Tloia!'
caesarCipher('Ebiil Tloia!', 23, true); // 'Hello World!'
JavaScript, Algorithm
Groups the given data into k
clusters, using the k-means clustering algorithm.
JavaScript, Algorithm
Finds the index of a given element in a sorted array using the binary search algorithm.
JavaScript, Algorithm
Finds the first index of a given element in an array using the linear search algorithm.