Difference between revisions of "Control Structures in PHP"

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 +
== if ==
 +
 
When compared to the C programming language, PHP is "lazy" as it will terminate processing of the if routing as soon as it determines the outcome.
 
When compared to the C programming language, PHP is "lazy" as it will terminate processing of the if routing as soon as it determines the outcome.
  
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   if (isset($var)) {
 
   if (isset($var)) {
 +
 +
== switch ==
 +
 +
Below is an IF struction and a SWITCH structure that both do the same thing. 
 +
-------------------------------------------------------------------------------
 +
<?php
 +
if ($i == 0) {
 +
    echo "i equals 0";
 +
} elseif ($i == 1) {
 +
    echo "i equals 1";
 +
} elseif ($i == 2) {
 +
    echo "i equals 2";
 +
}
 +
-------------------------------------------------------------------------------
 +
switch ($i) {
 +
case 0:
 +
    echo "i equals 0";
 +
    break;
 +
case 1:
 +
    echo "i equals 1";
 +
    break;
 +
case 2:
 +
    echo "i equals 2";
 +
    break;
 +
}
 +
?>
 +
 +
More examples using switch / case.
 +
 +
<?php
 +
switch ($i) {
 +
case "apple":
 +
    echo "i is apple";
 +
    break;
 +
case "bar":
 +
    echo "i is bar";
 +
    break;
 +
case "cake":
 +
    echo "i is cake";
 +
    break;
 +
}
 +
?>
 +
 +
----
 +
 +
<?php
 +
switch ($i) {
 +
case 0:
 +
    echo "i equals 0";
 +
    break;
 +
case 1:
 +
    echo "i equals 1";
 +
    break;
 +
case 2:
 +
    echo "i equals 2";
 +
    break;
 +
default:
 +
    echo "i is not equal to 0, 1 or 2";
 +
}
 +
?>
  
  

Latest revision as of 19:49, 23 May 2007

if

When compared to the C programming language, PHP is "lazy" as it will terminate processing of the if routing as soon as it determines the outcome. 

 if ( $comp == "open" ) {

 if (!empty($cfgRelation['relation'])) {

 if ($have_rel) {

 if (typeof(window.print) != 'undefined') {

 if (!empty($tbl_group) && !$cfg['ShowTooltipAliasTB']) {

 if (empty($var)) {

 if (isset($var)) {

switch

Below is an IF struction and a SWITCH structure that both do the same thing.  
-------------------------------------------------------------------------------
<?php
if ($i == 0) {
   echo "i equals 0";
} elseif ($i == 1) {
   echo "i equals 1";
} elseif ($i == 2) {
   echo "i equals 2";
} 
-------------------------------------------------------------------------------
switch ($i) {
case 0:
   echo "i equals 0";
   break;
case 1:
   echo "i equals 1";
   break;
case 2:
   echo "i equals 2";
   break;
}
?>

More examples using switch / case. 

<?php
switch ($i) {
case "apple":
   echo "i is apple";
   break;
case "bar":
   echo "i is bar";
   break;
case "cake":
   echo "i is cake";
   break;
}
?>


<?php
switch ($i) {
case 0:
   echo "i equals 0";
   break;
case 1:
   echo "i equals 1";
   break;
case 2:
   echo "i equals 2";
   break;
default:
   echo "i is not equal to 0, 1 or 2";
}
?>
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