Semicolons and infix operators

One issue with Scala’s semicolon convention is how to write expressions that span several lines. For instance

someLongExpression
+ someOtherExpression

would be interpreted as two expressions:

someLongExpression;
+ someOtherExpression

To overcome this problem you could write the multi-line expression in parentheses, because semicolons are never inserted inside (...):

(someLongExpression
+ someOtherExpression)

Source: Coursera: Blocks and lexical scope

syntax parentheses

or Read more about Scala Quizzes