String Interpolation with 's'

Processed String Literals

In string interpolation, we work with processed string literals. Processed string literals are simply string literals that require further work or processing during compilation by the compiler.

The s String Interpolator

For string interpolation with s, we prepend an s to any string literal. This allows us to use variables inside a string.

In our example above, s"I want to visit $country!" is a processed string literal.

Syntax for Single Variable Expressions

You can place any expression after the $. For a single variable expression, you can simply place the variable name after the $ and Scala will interpret all the characters until the last character of the variable identifier.

In our example above, the variable identifier was country. Scala interpreted the variable until the y of country and afterward, processed ! like any other character.

Let’s now try to embed a mathematical expression in a string. As a mathematical expression doesn’t have any identifiers, letting the compiler know what to interpret and what to take as a regular character is done by modifying the syntax for single variable expressions.

Syntax for Expressions with Non-Identifier Characters

The expression you want the Scala compiler to process will be placed in curly brackets. The opening curly bracket will immediately follow the $.

In the code above, 3+4 is our expression which the compiler processes and interprets to 7, as can be seen in the output when you press RUN.

Feel free to modify the above code snippets to get a better hang of string interpolation with s.

In the next lesson, you will be challenged to embed a variable in a string.