Control Structures

if/elseif/else

if ( $x == 5 ) {
	// do something
} elseif ( $x == 9 ) {
	// do something else
} elseif ( $x > 0 ) {
	// do a third thing
} else {
	// if all else fails, do this
}

if ( isset($y) ) {
	// Checks to see if the variable $y has a value
}

switch

switch ($x) {
	case 5:
		// do something
		break ;
	case 9:
		// do something else
		break ;
	default:
		// do your "otherwise" stuff here
}

Looping Structures

// for loop
for ( $i = 0; $i <= $max; $i++ ) {
	// statements to repeat
}

// while loop
// if $value starts out <= $max, the statements will NEVER run
while ( $value <= $max ) {
	// statements to repeat
	// Be sure to change $value in here!
}

// while loop
// will run at least once
do {
	// statements to repeat
} while ( $value <= $max ) ;

// foreach loop
for ( $presidents as $num => $name ) {
	// statements to repeat
	// We'll look at this in the section on Array variables
}