Added new algoritm

String/CheckWordOccurrence.js

@@ -0,0 +1,25 @@
+/**
+ * Check and count occurrence of each word in a string
+ * Inputs a String eg. Madonna and Boolean
+ */
+
+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')
+    }
+
+    let 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
+        }
+
+    }
+    return result;
+}
+export { checkWordOccurrence }