Statements And blocks

An expression becomes a statement as when it is followed by a semicolon:

var x = 5;
y = ++x * 7;
foo();

Braces { and } are used to group statements into a compound statement, so they are syntactically equivalent to a single statement:

{ y=z; foo(); }

The comma may be used to group several expressions into a single statement too:

y=z, foo();