added updated example codes (#2062)

core-java/src/main/java/com/baeldung/string/StringToCharStream.java

@@ -15,8 +15,18 @@ public class StringToCharStream {
         //let's use the Stream API to manipulate a string
         //this will count the occurrence of each character in the test string
 
+        String testString = "tests";
+
+        //first get an IntStream
+        IntStream intStream = testString.chars();
+        IntStream intStream1 = testString.codePoints();
+
+        //now let's map them
+        Stream<Character> characterStream = intStream.mapToObj(c -> (char) c);
+        Stream<Character> characterStream1 = intStream1.mapToObj(c -> (char) c);
+
         System.out.println("Counting Occurrence of Letter");
-            String testString = "Noww";
+        testString = "Noww";
 
         //we don't want to use foreach, so . . .
 
@@ -35,6 +45,7 @@ public class StringToCharStream {
 
         //printing out the result here
         System.out.println(map.toString());
+
     }
 
 

core-java/src/test/java/com/baeldung/string/StringToCharStreamUnitTest.java

@@ -5,7 +5,9 @@ import org.junit.Test;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
 
+import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
 /**
@@ -17,12 +19,13 @@ public class StringToCharStreamUnitTest {
 
     @Test
     public void givenTestString_whenChars_thenReturnIntStream() {
-         assertTrue(testString.chars() instanceof IntStream);
+
+        assertThat(testString.chars(), instanceOf(IntStream.class));
     }
 
     @Test
     public void givenTestString_whenCodePoints_thenReturnIntStream() {
-        assertTrue(testString.codePoints() instanceof IntStream);
+        assertThat(testString.codePoints(), instanceOf(IntStream.class));
     }
 
     @Test
@@ -33,4 +36,11 @@ public class StringToCharStreamUnitTest {
         assertNotNull("IntStream returned by codePoints() did not map to Stream<Character>", characterStream1);
     }
 
+    @Test
+    public void givenIntStream_whenMapToObj_thenReturnStringStream(){
+        Stream<String> stringStream
+                = testString.codePoints().mapToObj(c -> String.valueOf((char) c));
+        assertNotNull(stringStream);
+    }
+
 }