KTLN-631: Check Whether a Character is a Vowel or Consonant in Kotlin (#589)

* Added Unit test

* code fixes

* code fixes

* code fixes

* code fixes

* code changes

Author: nappy29

core-kotlin-modules/core-kotlin-8/src/test/kotlin/com/baeldung/vowelOrConsonant/VowelOrConsonantUnitTest.kt

@@ -0,0 +1,99 @@
+package com.baeldung.vowelOrConsonant
+
+import org.junit.jupiter.api.Test
+import kotlin.test.assertTrue
+import kotlin.test.assertFalse
+
+class VowelOrConsonantUnitTest {
+    val isLetterRegex = "[a-zA-Z]".toRegex()
+    val isVowelLetterRegex = "[AEIOUaeiou]".toRegex()
+    @Test
+    fun `using when expression`() {
+        assertTrue(isVowel('e'))
+        assertTrue(isVowel('I'))
+        assertTrue(isVowel('o'))
+        assertFalse(isConsonant('o'))
+        assertFalse(isVowel('H'))
+        assertTrue(isConsonant('H'))
+        assertFalse(isVowel('@'))
+        assertFalse(isConsonant('@'))
+    }
+
+    @Test
+    fun `using Map method`() {
+        assertTrue(isVowelUsingMap('e'))
+        assertTrue(isVowelUsingMap('I'))
+        assertTrue(isVowelUsingMap('o'))
+        assertFalse(isConsonantUsingMap('o'))
+        assertFalse(isVowelUsingMap('H'))
+        assertTrue(isConsonantUsingMap('H'))
+        assertFalse(isVowelUsingMap('@'))
+        assertFalse(isConsonantUsingMap('@'))
+    }
+
+    @Test
+    fun `using regex method`() {
+        assertTrue(isVowelUsingRegexMethod('e'))
+        assertTrue(isVowelUsingRegexMethod('I'))
+        assertTrue(isVowelUsingRegexMethod('o'))
+        assertFalse(isConsonantUsingRegex('o'))
+        assertFalse(isVowelUsingRegexMethod('H'))
+        assertTrue(isConsonantUsingRegex('H'))
+        assertFalse(isVowelUsingRegexMethod('@'))
+        assertFalse(isConsonantUsingRegex('@'))
+    }
+    @Test
+    fun `using ASCII values method`() {
+        assertTrue(isVowelUsingAsciiValues('E'))
+        assertTrue(isVowelUsingAsciiValues('I'))
+        assertTrue(isVowelUsingAsciiValues('o'))
+        assertFalse(isConsonantUsingAscii('o'))
+        assertFalse(isVowelUsingAsciiValues('H'))
+        assertTrue(isConsonantUsingAscii('H'))
+        assertFalse(isVowelUsingAsciiValues('@'))
+        assertFalse(isConsonantUsingAscii('@'))
+    }
+
+    fun isVowel(c: Char): Boolean {
+        return when (c) {
+            'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U' -> true
+            else -> false
+        }
+    }
+
+    fun isConsonant(c: Char): Boolean {
+        return !isVowel(c) && c.isLetter()
+    }
+
+    fun isVowelUsingMap(c: Char): Boolean {
+        val vowels = mapOf(
+            'a' to true,
+            'e' to true,
+            'i' to true,
+            'o' to true,
+            'u' to true )
+        return vowels.containsKey(c.lowercaseChar())
+    }
+
+    fun isConsonantUsingMap(c: Char): Boolean {
+        return !isVowelUsingMap(c) && c.isLetter()
+    }
+
+    fun isVowelUsingRegexMethod(c: Char): Boolean {
+        return c.toString().matches(isVowelLetterRegex)
+    }
+
+    fun isConsonantUsingRegex(c: Char): Boolean {
+        return !isVowelUsingRegexMethod(c) && c.toString().matches(isLetterRegex)
+    }
+
+    fun isVowelUsingAsciiValues(c: Char): Boolean {
+        val ascii = c.code
+        return ascii == 65 || ascii == 69 || ascii == 73 || ascii == 79 || ascii == 85 || ascii == 97 || ascii == 101 || ascii == 105 || ascii == 111 || ascii == 117
+    }
+
+    fun isConsonantUsingAscii(c: Char): Boolean {
+        val ascii = c.code
+        return (ascii in 65..90 || ascii in 97..122) && !isVowelUsingAsciiValues(c)
+    }
+}