Control Structures in Java

The body of a method in Java consists of a block which encloses a sequence of statements in braces.

So far we have seen (more or less) following statements:

Name Syntax and Examples

Declaration
Modifier Type Identifier Initializer ;

int i;

final double pi = 3.14159265358979323846;

Expression Statement Expression ;

this.gallons = this.gallons + gallons;

log = new FuelLog(initialMileage);

log.fillUp(mileage, gallons);

Return Statement return Expression ;

return (mileage - initialMileage) / gallons;

return;

Empty Statement ;

Block Statement
{ Statement₁ Statement₂ ... }

{ int i; i = 1; }

{}

{;}

{ int i; { int j = i; int i = j; } int j; }

So far all statements were executed just once per invocation of the method exactly in the order given. There were no repetitions nor selections of statements.

Statements that support repetition and conditional execution are called control statements or control structures.