added: my solutions in javascript to the caesar cipher challenge

challenges/easy/caesar-cipher/solutions/valentinadagata/main.js

@@ -0,0 +1,47 @@
+const letters = 26;
+
+function encode(str, shift) {
+  let new_shift  = shift % letters
+
+  return str.split("").map(character => {
+      // if is a letter
+      if ((character >= "a" && character <= "z") || (character >= "A" && character <= "Z")) {
+
+        // if is uppercase
+        let ascii = 65
+
+        // if is lowercase
+        if (character >= "a" && character <= "z") {
+          ascii = 97
+        }
+
+        let new_str = (letters + character.charCodeAt(0) - ascii + new_shift) % letters
+        let encrypt = String.fromCharCode(new_str + ascii)
+        return encrypt
+      }
+      // don't encrypt if it's not a letter
+      else return character;
+  }).join("");
+}
+
+
+function decode(str, shift) {
+  new_shift = -shift
+  return encode(str, new_shift)
+}
+
+
+/*
+// encode test
+console.log(encode('Hello, World!', 7)); // => 'Olssv, Dvysk!'
+console.log(encode('I love pizza.', -7)); // => 'B ehox ibsst.'
+console.log(encode('HytyQapgnr kyicq qclqc. Qmkcrgkcq.', 50)); // => 'HytyQapgnr kyicq qclqc. Qmkcrgkcq.'
+console.log(encode('abc', 24));  // => 'yza'
+
+
+// decode test
+console.log(decode('CxvxaaxfMneb Axltb!', 9)); // => 'TomorrowDevs Rocks!'
+console.log(decode('Gtdflw Defotz Nzop td rcple!!!', -15)); // => 'Visual Studio Code is great!!!'
+console.log(decode('Vriwzduh Hqjlqhhulqj', 3)); // => 'Software Engineering'
+console.log(decode("Buj'i mhyju jxu syfxuh.", 120)); // => "Let's write the cipher."
+*/