fix: change location of others to correct places (#5559)

src/test/java/com/thealgorithms/strings/CountCharTest.java

@@ -0,0 +1,24 @@
+package com.thealgorithms.strings;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+class CountCharTest {
+
+    @ParameterizedTest(name = "\"{0}\" should have {1} non-whitespace characters")
+    @CsvSource({"'', 0", "'   ', 0", "'a', 1", "'abc', 3", "'a b c', 3", "'   a   b   c   ', 3", "'\tabc\n', 3", "'  a   b\tc  ', 3", "' 12345 ', 5", "'Hello, World!', 12"})
+    @DisplayName("Test countCharacters with various inputs")
+    void testCountCharacters(String input, int expected) {
+        assertEquals(expected, CountChar.countCharacters(input));
+    }
+
+    @Test
+    @DisplayName("Test countCharacters with null input")
+    void testCountCharactersNullInput() {
+        assertEquals(0, CountChar.countCharacters(null));
+    }
+}