How to use Do-While Loop in PHP?

[Zavier]

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Hello friends,
I am new to the PHP programming language. I want to know about the do-while loop that is used in PHP. I have used that loop before but in other programming language. There should be some different way to use it in PHP. So thought to ask you guys, since you explain the topic more clearly. Please tell me how to use Do-While Loop in PHP? I am not so good in PHP, so please explain me in simple language.!!

[Deabelos]

You can run the piece of code again and again by using the while loop in PHP. I would like to explain you about the while loop so that you can understand the basic concept very clearly. The while loop is the easiest way to implement a loop in PHP. This loop behaves the same way as in C. The simplest example of a while loop is as follows :

PHP Code:

while (expr)
    statement 


[Viensterrr]

Even I am explaining you more about the while loop because once you know about the while loop, you can easily understand the do-while loop. The meaning of a while statement is simple. It tells PHP to execute the nested statement(s) repeatedly, as long as the while expression evaluates to TRUE. The value of the expression is checked each time at the beginning of the loop, so even if this value changes during the execution of the nested statement(s), execution will not stop until the end of the iteration. You should know that each time PHP runs the statements in the loop is one iteration. Sometimes, if the while expression evaluates to FALSE from the very beginning, the nested statement(s) won't even be run once.

[Solitario]

As with the if you can group multiple statements within the same while loop by grouping them within parentheses or by using the following syntax :

PHP Code:

while (expr):
    statement
    ...
endwhile; 


PHP executes the statement as an expression of the while loop is evaluated as TRUE. The value of the expression is checked at the beginning of each loop, and if the value changes during the execution of the statement, execution will not stop until the end of the iteration

[kyosang]

The do-while loops are very similar to while loops, but the expression is checked at the end of each iteration rather than the beginning. The main difference from regular while loops is that the first iteration of the do-while loop is always executed where the expression is checked at the end of the iteration, which is not the case when you use a while loop. The condition is checked at the beginning of each iteration, and if it is FALSE from the very beginning, the loop will be stopped immediately.

[Warner]

The following is the syntax for do-while loops :

PHP Code:

<?php
$i = 0;
do {
    echo $i;
} while ($i > 0);
?>

The above loop would run only once, because when the expression is evaluated, it is FALSE (because the variable $ i is not greater than 0) and the execution of the loop 's stops.