Added doctest to string_switch_case.py (TheAlgorithms#11136)

* Added doctest to string_switch_case.py

* Update string_switch_case.py

Author: Suyashd999

Diff for: strings/string_switch_case.py

@@ -28,6 +28,12 @@ def to_simple_case(str_: str) -> str:
     """
     >>> to_simple_case("one two 31235three4four")
     'OneTwo31235three4four'
+    >>> to_simple_case("This should be combined")
+    'ThisShouldBeCombined'
+    >>> to_simple_case("The first letters are capitalized, then string is merged")
+    'TheFirstLettersAreCapitalizedThenStringIsMerged'
+    >>> to_simple_case("special characters :, ', %, ^, $, are ignored")
+    'SpecialCharactersAreIgnored'
     """
     string_split = split_input(str_)
     return "".join(
@@ -37,6 +43,14 @@ def to_simple_case(str_: str) -> str:
 
 def to_complex_case(text: str, upper: bool, separator: str) -> str:
     """
+    Returns the string concatenated with the delimiter we provide.
+
+    Parameters:
+    @text: The string on which we want to perform operation
+    @upper: Boolean value to determine whether we want capitalized result or not
+    @separator: The delimiter with which we want to concatenate words
+
+    Examples:
     >>> to_complex_case("one two 31235three4four", True, "_")
     'ONE_TWO_31235THREE4FOUR'
     >>> to_complex_case("one two 31235three4four", False, "-")