caesars-cipher-encrypt.html

<!DOCTYPE html>
<html>
<body>


<script>
//https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/javascript-algorithms-and-data-structures-projects/caesars-cipher
//Write a function which takes a ROT13 encoded string as input and returns a decoded string.
//All letters will be uppercase. Do not transform any non-alphabetic character (i.e. spaces, punctuation), but do pass them on.

function rot13(str) {
var newArr = str.split("");
newArr= newArr.map(letter => letter.charCodeAt());
var lastArr = [];
for (var i=0; i<newArr.length; i++) {
    if (newArr[i] >= 65 && newArr[i] <= 90) {
        newArr[i] = ((((newArr[i] + 13)-65)%26)+65);
        lastArr.push(newArr[i]);
    } else {
        lastArr.push(newArr[i]);
    }
}
return lastArr.map(a => String.fromCharCode(a)).join("");

}

//tests
console.log(rot13("SERR PBQR PNZC"));
console.log(rot13("SERR CVMMN!"));
console.log(rot13("SERR YBIR?"));
console.log(rot13("GUR DHVPX OEBJA SBK WHZCF BIRE GUR YNML QBT."));


</script>

</body>
</html>