KTLN-453: Convert String to Char in Kotlin (#803)

* pom kotlin version

* pom version

* Added unit tests

Author: nappy29

core-kotlin-modules/core-kotlin-strings-4/src/test/kotlin/com/baeldung/stringToChar/StringToCharUnitTest.kt

@@ -0,0 +1,48 @@
+package com.baeldung.stringToChar
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+
+class StringToCharUnitTest {
+
+    @Test
+    fun `converts string to char using get method`(){
+        val str = "H"
+        val char = str.get(0)
+
+        assertEquals('H', char)
+    }
+
+    @Test
+    fun `converts string to char using index operator method`(){
+        val str = "H"
+        val char = str[0]
+
+        assertEquals('H', char)
+    }
+
+    @Test
+    fun `converts string to char using single method`(){
+        val str = "H"
+        val char = str.single()
+
+        assertEquals('H', char)
+    }
+
+    @Test
+    fun `converts string to char using first method`(){
+        val str = "H"
+        val char = str.first()
+
+        assertEquals('H', char)
+    }
+
+    @Test
+    fun `converts string to char using toCharArray method`(){
+        val str = "H"
+        val charArray = str.toCharArray()
+        val char = charArray[0]
+
+        assertEquals('H', char)
+    }
+}