For Loop

for ($i=0; $i<=2; $i++)
echo 'i = '.$i.'<br /><br />';

Results:

i = 0
i = 1
i = 2

While Loop (may not b e executed at all)

$i=1;
while ( $i<4 )
{
echo 'i='.$i.'<br />';
$i++;
}

Results:

i=1
i=2
i=3

Do..While Loop (always executed at least once)

$i=1;
do
{
echo 'i='.$i.'<br />';
$i++;
}
while ( $i<4 )

Results:

i=1
i=2
i=3

foreach Loop

$ron2[0]='A';
$ron2[1]='B';
$ron2[2]='C';

foreach ($ron2 as $key => $value){
echo "the value at $key is $value.<br />";
}

Results:

the value at 0 is A.
the value at 1 is B.
the value at 2 is C.

Breaking out of a loop or script

break;  //goes to the next line after  the loop

continue;  // goes to the top of the loop and continues iteration

exit; //exits script

die; 

Die Example 1: mysql_query($query) or die ('Could not execute query.');

Die Example 2:

function err_msg()

{

echo 'MySQL error was: ';
echo mysql_error();

}

mysql_query($query) or die (err_msg());