merge: Fixed wordOccurrence algorithm (TheAlgorithms#909)

* resolved: upgrade the algoritm

* docs: add js doc

Author: fahimfaisaal

String/CheckWordOccurrence.js

@@ -1,25 +1,30 @@
 /**
-  * Check and count occurrence of each word in a string
-  * Inputs a String eg. Madonna and Boolean
-  **/
-
+ * @function checkWordOccurrence
+ * @description - this function count all the words in a sentence and return an word occurrence object
+ * @param {string} str
+ * @param {boolean} isCaseSensitive
+ * @returns {Object}
+ */
 const checkWordOccurrence = (str, isCaseSensitive = false) => {
   if (typeof str !== 'string') {
     throw new TypeError('The first param should be a string')
   }
+
   if (typeof isCaseSensitive !== 'boolean') {
     throw new TypeError('The second param should be a boolean')
   }
 
-  const result = {}
-  if (str.length > 0) {
-    for (let i = 0; i < str.length; i++) {
-      const word = isCaseSensitive ? str[i] : str[i].toUpperCase()
-      if (/\s/.test(word)) continue
-      result[word] = (!result[word]) ? 1 : result[word] + 1
-    }
-  }
+  const modifiedStr = isCaseSensitive ? str.toLowerCase() : str
 
-  return result
+  return modifiedStr
+    .split(/\s+/) // remove all spaces and distribute all word in List
+    .reduce(
+      (occurrence, word) => {
+        occurrence[word] = occurrence[word] + 1 || 1
+        return occurrence
+      },
+      {}
+    )
 }
+
 export { checkWordOccurrence }

String/test/CheckWordOcurrence.test.js

@@ -1,33 +1,29 @@
 import { checkWordOccurrence } from '../CheckWordOccurrence'
-describe('checkWordOccurrence', () => {
+
+describe('Testing checkWordOccurrence', () => {
   it('expects throw on insert wrong string', () => {
     const value = 123
+
     expect(() => checkWordOccurrence(value)).toThrow()
   })
+
   it('expect throw on insert wrong param for case sensitive', () => {
     const value = 'hello'
+
     expect(() => checkWordOccurrence(value, value)).toThrow()
   })
+
   it('check occurrence with case sensitive', () => {
-    const stringToTest = 'A Mad World'
-    const charsOccurrences = checkWordOccurrence(stringToTest, true)
-    const expectResult = { A: 1, M: 1, a: 1, d: 2, W: 1, l: 1, o: 1, r: 1 }
-    const occurrencesObjectKeys = Object.keys(charsOccurrences)
-    const expectObjectKeys = Object.keys(expectResult)
-    expect(occurrencesObjectKeys.length).toBe(expectObjectKeys.length)
-    expectObjectKeys.forEach(key => {
-      expect(expectResult[key]).toBe(charsOccurrences[key])
-    })
+    const stringToTest = 'The quick brown fox jumps over the lazy dog'
+    const expectResult = { The: 1, quick: 1, brown: 1, fox: 1, jumps: 1, over: 1, the: 1, lazy: 1, dog: 1 }
+
+    expect(checkWordOccurrence(stringToTest)).toEqual(expectResult)
   })
+
   it('check occurrence with case insensitive', () => {
-    const stringToTest = 'A Mad World'
-    const charsOccurrences = checkWordOccurrence(stringToTest, false)
-    const expectResult = { A: 2, D: 2, L: 1, M: 1, O: 1, R: 1, W: 1 }
-    const occurrencesObjectKeys = Object.keys(charsOccurrences)
-    const expectObjectKeys = Object.keys(expectResult)
-    expect(occurrencesObjectKeys.length).toBe(expectObjectKeys.length)
-    expectObjectKeys.forEach(key => {
-      expect(expectResult[key]).toBe(charsOccurrences[key])
-    })
+    const stringToTest = 'The quick brown fox jumps over the lazy dog'
+    const expectResult = { the: 2, quick: 1, brown: 1, fox: 1, jumps: 1, over: 1, lazy: 1, dog: 1 }
+
+    expect(checkWordOccurrence(stringToTest, true)).toEqual(expectResult)
   })
 })