ASP/PHP/Javascript/SQL Cross Reference

Python/Applescript cross reference.

if x=100 then
x=x+5 
elseif x<200 then 
x=x+2 
else 
x=x+1 
end if

if ($x==100) { 
$x=$x+5; 
} 
else if ($x<200) { 
$x=$x+2; 
} 
else { 
$x++; 
}

for x=0 to 100 step 2 
if x>p then exit for
next

for ($x=0; $x<=100; $x+=2) { 
if ($x>$p) {break;}
}

do while x<100 
x=x+1 
if x>p then exit do
loop

while ($x<100) { 
$x++; 
if ($x>$p) {break;}
}

select case chartName
case "TopSales"
theTitle="Best Sellers"
theClass="S"
case "TopSingles"
theTitle="Singles Chart"
theClass="S"
case "TopAlbums"
theTitle="Album Chart"
theClass="A"
case else
theTitle="Not Found"
end select

switch ($chartName) {
case "TopSales":
$theTitle="Best Sellers"; $theClass="S";
break;
case "TopSingles":
$theTitle="Singles Chart"; $theClass="S";
break;
case "TopAlbums":
$theTitle="Album Chart"; $theClass="A";
break;
default:
$theTitle="Not Found";
}

Function myFunction(x)
myFunction = x*16  'Return value
End Function

function myFunction($x) {
return $x*16;  //Return value
}

PHP 4 to PHP 5 differences

PHP 5's major new achievements come in the area of its exception handling and a new object that introduces features that bring true OOP to PHP. Exception handling was certainly one of the most noticeable missing features in PHP 4, and its addition to PHP 5 is certainly a sign of maturity. Exception handling means you have language defined and standardized ways of handling errors in your software. Just use the try, catch, and throw methods, and your PHP code becomes more robust and clean.

<?php

class blue {

  function openFile ($inFile) {
    if (file_exists ($inFile)) {
      # code to open the file here
    } else {

      throw new Exception
	("Cannot open file: $inFile");
    }
  }
}

$blueObj = new blue ();

try {
  $blueObj->openFile ('/home/shull/file.txt');

} catch (Exception $myException) {
  echo $myException->getMessage ();

  # rest of exception handling code here

}

# rest of blue methods here

?>

The new object model has a number of positive impacts on programs written in PHP. In PHP 4, when an object was passed to a function or method, it was passed by value, unless you explicitly told PHP otherwise. This procedure meant that a copy of that object, all the data structures in memory, would have to be copied. This step used memory and made access slow and clunky. In PHP 5, however, objects are always passed by reference.

The new object-oriented features in PHP 5, including constructors and destructors, are noteworthy. As with C++ and Java, they provide a standard way to create the object, allocate memory, and do any necessary setup via a constructor method and perform cleanup with a destructor method.

PHP 5 also introduces more subtle control of methods and variables in your classes. In PHP 4, everything was public: You could access variables from your classes outside the class or in derived classes. In PHP 5, you can still make variables or methods public, but you can also make them private, so they're used only within the class itself. A third option is to make them protected, which means that methods and variables can be viewed within the class or when subclassed.

Furthermore, PHP 5 introduces type hinting, or better type checking. When you pass an object into a routine, PHP can check that it is the right type and give a type-mismatch error if the check fails.

Additional features such as static methods and variables and abstract classes exist, so be sure to check the documentation for details.