PHP while Loop Statement


Suppose you want to calculate gross salaries of 20 different persons or take a list of maximum and minimum temperatures of a certain month or a year, the while loop is ideal to solve these types of cases.

The while statement is simple, it executes the statement(s) repeatedly as long as the condition is true. The condition is checked every time at the beginning of the loop.


while ( condition is true )
execute this statement ;
The general form of while statement :
        initialize loop counter;
while (test loop counter using condition)
execute the statement
increment loop counter

Example :

The following example print "Increment Number" with $x1 value as well as "Hello world" five times.

while ($x1<=5)
echo "Increment Number : $x1 <br />";>
echo "Hello World <br />";

Output :

Increment Number : 1 
Hello World 
Increment Number : 2 
Hello World 
Increment Number : 3 
Hello World 
Increment Number : 4 
Hello World
Increment Number : 5 
Hello World

View the example in the browser

Pictorial representation of while loop


See also

do while, for statement

Previous: if else elseif statement
Next: do-while statement

PHP: Tips of the Day

PHP: Convert one date format into another in PHP

The second parameter to date() needs to be a proper timestamp (seconds since January 1, 1970). You are passing a string, which date() can't recognize.

You can use strtotime() to convert a date string into a timestamp. However, even strtotime() doesn't recognize the y-m-d-h-i-s format.

PHP 5.3 and up

Use DateTime::createFromFormat. It allows you to specify an exact mask - using the date() syntax - to parse incoming string dates with.

PHP 5.2 and lower

You will have to parse the elements (year, month, day, hour, minute, second) manually using substr() and hand the results to mktime() that will build you a timestamp.

But that's a lot of work! I recommend using a different format that strftime() can understand. strftime() understands any date input short of the next time joe will slip on the ice. for example, this works:

$old_date = date('l, F d y h:i:s');         // returns Saturday, January 30 10 02:06:34
$old_date_timestamp = strtotime($old_date);
$new_date = date('Y-m-d H:i:s', $old_date_timestamp);

Ref : https://bit.ly/33QzKPG