merge: added reduceRight & trim method (TheAlgorithms#961)

Author: fahimfaisaal

String/ReverseWords.js

@@ -1,16 +1,17 @@
+/**
+ * @function reverseWords
+ * @param {string} str
+ * @returns {string} - reverse string
+ */
 const reverseWords = (str) => {
   if (typeof str !== 'string') {
     throw new TypeError('The given value is not a string')
   }
-  // Split string into words
-  // Ex. "I Love JS" => ["I", "Love", "JS"]
-  const words = str.split(' ')
-  // reverse words
-  // ["I", "Love", "JS"] => ["JS", "Love", "I"]
-  const reversedWords = words.reverse()
-  // join reversed words with space and return
-  // ["JS", "Love", "I"] => "JS Love I"
-  return reversedWords.join(' ')
+
+  return str
+    .split(/\s+/) // create an array with each word in string
+    .reduceRight((reverseStr, word) => `${reverseStr} ${word}`, '') // traverse the array from last & create an string
+    .trim() // remove the first useless space
 }
 
-export { reverseWords }
+export default reverseWords

String/test/ReverseWords.test.js

@@ -1,12 +1,6 @@
-import { reverseWords } from '../ReverseWords'
-
-describe('reverseWords', () => {
-  it('expects to reverse words to return a joined word', () => {
-    expect(reverseWords('I Love JS')).toBe('JS Love I')
-    expect(reverseWords('Hello World')).toBe('World Hello')
-    expect(reverseWords('The Algorithms Javascript')).toBe('Javascript Algorithms The')
-  })
+import reverseWords from '../ReverseWords'
 
+describe('Testing the reverseWords function', () => {
   it.each`
     input
     ${123456}
@@ -21,4 +15,10 @@ describe('reverseWords', () => {
       }).toThrow('The given value is not a string')
     }
   )
+
+  it('expects to reverse words to return a joined word', () => {
+    expect(reverseWords('I Love JS')).toBe('JS Love I')
+    expect(reverseWords('Hello World')).toBe('World Hello')
+    expect(reverseWords('The Algorithms Javascript')).toBe('Javascript Algorithms The')
+  })
 })