The method to convert characters such as the numerical expression ''' in a JSON file to special characters like single quotation marks is to use the appropriate escape sequence. In this case, the escape sequence for a single quote (') is '\''.
So, any instances of ''' in the JSON file should be replaced with '\''. For example, the JSON string "{ 'name': 'John's Pizza' }" would become "{ 'name': 'John\'s Pizza' }".
