Strings in expressions have always to be marked by basic or double quotes. ="String" or ='String'
For the display of quotes in strings the quote can be entered double.
=" "" " or =' '' '. Just as well a quote can be emitted,
if instead of a duplication the in each case other quote type for the string design is used: =" ' " or =' " '
Unicode characters can be specified with a trailing \u and the
following codepoint definition within a string definition.
Example: "\u20ac" for the € character.