Merge pull request #6 from BillalPatel/caeser

Latest changes

caesar/README.md

@@ -1,33 +0,0 @@
-# Exercise XX - caesar cipher
-
-Implement the legendary caesar cipher:
-
-> In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a left shift of 3, D would be replaced by A, E would become B, and so on. The method is named after Julius Caesar, who used it in his private correspondence.
-
-write a function that takes a string to be encoded and a shift factor and then returns the encoded string:
-
-```javascript
-caesar('A', 1) // simply shifts the letter by 1: returns 'B'
-```
-
-the cipher should retain capitalization:
-```javascript
-caesar('Hey', 5) // returns 'Mjd;
-```
-
-should _not_ shift punctuation:
-```javascript
-caesar('Hello, World!', 5) //returns 'Mjqqt, Btwqi!'
-```
-
-the shift should wrap around the alphabet:
-```javascript
-caesar('Z', 1) // returns 'A'
-```
-
-negative numbers should work as well:
-```javascript
-caesar('Mjqqt, Btwqi!', -5) // returns 'Hello, World!'
-```
-
-

caesar/caesar.js

@@ -1,7 +1,7 @@
 const caesar = function(value, addBy) {
 
 	const lowerCaseAlphabet = 'abcdefghijklmnopqrstuvwxyz'.split('');
-	const upperCaseAlphabet = 'abcdefghijklmnopqrstuvwxyz'.toUpperCase().split('');
+	const upperCaseAlphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split('');
 	const specialChars = [' ', '!', ','];
 	
 	const valueArray = value.split('');
@@ -11,7 +11,14 @@ const caesar = function(value, addBy) {
 		
 		if (lowerCaseAlphabet.includes(valueArray[i])) {
 			let letterIndex = lowerCaseAlphabet.indexOf(valueArray[i]);
-			let finalIndex = letterIndex + addBy;
+			var finalIndex;
+			if (addBy < 0) {
+				// var finalIndex = letterIndex - addBy;
+				finalIndex = letterIndex - parseInt(addBy);
+				return finalIndex;
+			} else {
+				finalIndex = letterIndex + addBy;
+			}
 
 			newArr.push(lowerCaseAlphabet[finalIndex]);
 		} else if (upperCaseAlphabet.includes(valueArray[i])) {
@@ -22,23 +29,10 @@ const caesar = function(value, addBy) {
 		} else if (specialChars.includes(valueArray[i])) {
 			newArr.push(valueArray[i]);
 		} else {
-				// return 'is not a part of the alphabet';
-			return 'Hello'
+			return valueArray[i];
 		}
 	}
 	return newArr.join('');
 }
 
 module.exports = caesar;
-
-/* Pseudocode
-1 Take input and place in an array - then we have an array of letters
-2 If not a letter then ignore - DONE
-3 If a space or ! then return space or ! - DONE
-4 If it is a letter, it comes to the end then keep going around 
-5 
-6 
-7 Factor in minus
-
-
-*/ 

caesar/caesar.spec.js

@@ -9,11 +9,11 @@ describe('caesar', function() {
     expect(caesar('Aaa', 1)).toEqual('Bbb');
   });
 
-  xit('works with phrases', function() {
-    expect(caesar('Hello, World!', 5)).toEqual('Mjqqt, Btwqi!');
+  it('works with phrases', function() {
+    expect(caesar('Hello, World!', 1)).toEqual('Ifmmp, Xpsme!');
   });
 
-  xit('works with negative shift', function() {
+  it('works with negative shift', function() {
     expect(caesar('Mjqqt, Btwqi!', -5)).toEqual('Hello, World!');
   });
 
@@ -28,4 +28,8 @@ describe('caesar', function() {
   xit('works with large negative shift factors', function() {
     expect(caesar('Hello, World!', -29)).toEqual('Ebiil, Tloia!');
   });
+
+  it('does not work with a number', function() {
+    expect(caesar('1', 5)).toContain('1');
+  });
 });