A do while loop differs from a while loop in that it always executes a block of code at least once even if the condition below evaluates to false. This is because it executes a block of code first and then checks the condition which is below the block of code.

The general format is:

do {

execute this code;

}

while(certain condition);

Example:

$price = 5;

do {

echo $price."<br>";

$price++;

}

while ($price < 10 );

The above will output:

5
6
7
8
9

We set our variable $price with a start value of 5. Since do while loops always execute the block of code at least once, $price has value of 5 and is echoed as 5. Then $price is incremented by 1 and $price now has value of 6.

Since $price of value of 6 is still less than 10 (in our condition), 6 is echoed, then incremented by 1 to 7 and so forth until the value of 9 has echoed. Then $price has value of 9 + 1 and is not less than 10 anymore so our code stops executing.