Add check vowels algorithm (#2314)

strings/CheckVowels.java

@@ -0,0 +1,48 @@
+package strings;
+
+/**
+ * Vowel Count is a system whereby character strings are placed in order based on the
+ * position of the characters in the conventional ordering of an alphabet. Wikipedia:
+ * https://en.wikipedia.org/wiki/Alphabetical_order
+ */
+class CheckVowels{
+    public static void main(String[] args) {
+        assert !hasVowels("This is a strings");
+        assert hasVowels("Hello World");
+        assert hasVowels("Java is fun");
+        assert !hasVowels("123hi");
+        assert hasVowels("Coding vs Programming");
+    }
+    
+  /**
+   * Check if a string is has vowels or not
+   *
+   * @param input a string
+   * @return {@code true} if given string has vowels, otherwise {@code false}
+   */
+    public static boolean hasVowels(String input){
+        if(input.matches("[AEIOUaeiou]")){
+            countVowels(input);
+            return true;
+        }
+        return false;
+    }
+    /**
+     * count the number of vowels
+     *
+     * @param input a string
+     * prints the count of vowels
+     */
+    public static void countVowels(String input){
+        input.toLowerCase();
+        int count=0;
+        int i=0;
+        while(i<input.length()){
+            if(input.charAt(i)=='a' || input.charAt(i)=='e'||input.charAt(i)=='i'||input.charAt(i)=='o'||input.charAt(i)=='u' ){
+                count++;
+            }
+            i++;
+        }
+        System.out.println(count);
+    }
+}