... Alternative syntax for control structures . ... Any PHP script is built out of a series of statements. A statement can be an assignment, a function call, a loop, a conditional statement of even a statement that does nothing (an empty statement). ... In addition, statements can be grouped into a statement-group by encapsulating a group of statements with curly braces. ... if (expr) statement . As described in the section about expressions , expr is evaluated to its Boolean value. ...