PHP/Statement/While loop

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Approximating a square root

   <source lang="html4strict">

<HTML> <HEAD> <TITLE>Approximating a square root</TITLE> </HEAD> <BODY> <?php $target = 81; $guess = 1.0; $precision = 0.0000001; $guess_squared = $guess * $guess; while (($guess_squared - $target > $precision) or ($guess_squared - $target < - $precision)) {

 print("Current guess: $guess is the square root of $target
"); $guess = ($guess + ($target / $guess)) / 2; $guess_squared = $guess * $guess;

} print("$guess squared = $guess_squared
"); ?> </BODY> </HTML>

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A sample while loop that counts to 10

   <source lang="html4strict">

<?php $num = 1; while ($num <= 10){

   print "Number is $num
"; $num++;

} print "Done."; ?>

 </source>
   
  


A while Statement

   <source lang="html4strict">


<html> <head> <title>A while Statement</title> </head> <body> <?php $counter = 1; while ( $counter <= 12 ) {

   print "$counter times 2 is ".($counter*2)."
"; $counter++;

} ?> </body> </html>


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Convert the while statement into a for statement?

   <source lang="html4strict">

<? $num = 1; while ( $num <= 49 ) {

 print "$num
"; $num += 2;

} for ( $num = 1; $num <= 49; $num += 2 ) {

 print "$num
\n";

} ?>

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Create a while statement that prints every odd number between 1 and 49

   <source lang="html4strict">

<? $num = 1; while ( $num <= 49 ) {

 print "$num
"; $num += 2;

} ?>

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Fahrenheit and Celsius table by while loop

   <source lang="html4strict">

$fahr = -50; $stop_fahr = 50;

print ""; print "";

while ($fahr <= $stop_fahr) {

   $celsius = ($fahr - 32) * 5 / 9;
print "";
   $fahr += 5;

}

print "
FahrenheitCelsius
$fahr$celsius
";
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Infinite Loops

   <source lang="html4strict">

<?php

           while(1) {
                   print "In loop!\n";
           }
   ?>

As "1" also evaluates to true, that loop will continue on forever.

   <?php
           for (;;) {
                   print "In loop!\n";
           }
   ?>
 
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Printing a <select> menu with while()

   <source lang="html4strict">

<? $i = 1; print "<select name="people">"; while ($i <= 10) {

   print "<option>$i</option>\n";
   $i++;

} print "</select>"; ?>

 </source>
   
  


The do...while Statement

   <source lang="html4strict">

<html> <head> <title>The do...while Statement</title> </head> <body>

<?php

   $num = 1;
   do {
     print "Execution number: $num
\n"; $num++; } while ( $num > 200 && $num < 400 );

?>

</body> </html>

 </source>
   
  


while and loop counter

   <source lang="html4strict">

<?php

  $count = 1;
  while ($count < 5) {
     echo "$count squared = ".pow($count,2). "
"; $count++; }

?>

 </source>