some condition changes

Author: Omkaragrawal

src/_Classics_/caeser_cipher/caeserCipher.js

@@ -4,16 +4,16 @@
 */
 function caesarCipher(toEncipher, shift = 0) {
     // If required for very strict shift checking then remove '=0'
-    if (typeof (Number(shift)) !== 'number') {
-        return Error('Invalid Shift Provided')
+    if (typeof (Number(shift)) !== 'number' && (shift !== NaN || shift !== 'NaN' || Number(shift) !== NaN )) {
+    throw Error('Invalid Shift Provided')
     } else {
         shift = Number(shift);
     }
 
-    if(typeof(toEncipher) === 'string' || typeof(toEncipher) === 'number') {
+    if(typeof(toEncipher) === 'string' || (typeof(toEncipher) === 'number' && toEncipher !== NaN)) {
         toEncipher = String(toEncipher);
     } else {
-        return Error('Invalid string provided');
+        throw Error('Invalid string provided');
     }
 
     // These are the valid entries aacepted, you can change it according to requirements