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quick question regarding c and php.

I know a bit of C and Kalle here (whos on the php team) has shown me some useful c source!

Just wondering since I am a .net developer (and I dont have PHP installed)
what would the following C code converted to PHP yield?

Code:



main()

{

        int x = 10;

        while(x) {

                x--;

                printf("X Value: %d\n", x);

        }



        



}

I've attempted to code it to make it easier for you guys to copy and paste:

Code:

<?PHP



$x = 10;

while ($x)

{

$x = $x - 1;

echo $x

}





?>

My question is will the PHP code be stuck in a infinite loop? I ask because C code parses true and false as 1 and 0, and therefore when that "x" value eaches zero, its assumed "false" and the while loop exits

Install PHP! It's actually fairly easy. Download Apache, download PHP, off you go.

PHP considers true and false 1 and 0 respectively as well, and the script stops at 0.
-m

OR you can be lazy and install WampServer2 and I'm pretty sure php supports $x-- and --$x the latter being the faster.

post or pre incrementing/decrementing depends on what you need the script to do, both can produce very different results, consider this:

PHP Code:


		
			
<?php

$a = $b = 1;

$c = ++$a;
$d = $b++;

printf('$a: %d <br /> $b: %d <br /> $c: %d <br /> $d: %d',$a, $b, $c, $d);

This script may not produce the results expected. In this script we set up our base vars ($a, $b) next we create $c and assign it the the value of ++$a, in other words 'Increment $a then put then assign $c the value'. Next we create $d and assign it the the value of $b++, in other words 'Assign $d the value of $b, then increment $b'. If we were to print this it would produce:

Code:

The speed difference comes because when you use post increment or decrement ($i++) PHP copies the value to a tmp variable, then it increments the value and returns the value which was stored before the incrementation, pre increment/decrement however does not, it just returns the value of the variable +/- 1

Anyway back to the topic, yes you are right C has no native boolean type (to my knowledge, prior to C99)
, instead you use 0 or 1 to flag true or false or you can use #define's or enum's:

Code:

#define TRUE  1

#define FALSE 0    

//or

typedef enum { FALSE, TRUE } boolean;

or user C99's stdbool:

c Code:

#include<stdbool>
bool boolean = true;
//etc

However php considers all these values as (Boolean)FALSE:

the boolean FALSE itself
the integer 0 (zero)
the float 0.0 (zero)
the empty string, and the string "0"
an array with zero elements
an object with zero member variables (PHP 4 only)
the special type NULL (including unset variables)
SimpleXML objects created from empty tags

taken from: PHP: Booleans - Manual

Thanks for the answers.

.NET is unable to do it because of strong types. It will not compile because "int can not be converted to boolean".

I just tried it with Java, and java does not seem to compile as well.

Awesome, by the way is Apache really neccessary? I have IIS 7 so I am just thinking to install PHP on that.

Quote:

I just tried it with Java, and java does not seem to compile as well.

Java doesn't allow an integer expression where by false is (int)0 and true is any non-zero value, as boolean variables are represented by the primitive type 'boolean' and java doesn't allow casting to and from boolean i believe (my java is a bit sketchy).

Quote:

Awesome, by the way is Apache really neccessary? I have IIS 7 so I am just thinking to install PHP on that.

No not at all, you can install and use PHP in a variety of ways, including on a command line interface. I am not sure of how to install on IIS as i don't usually use windows that often, but I'm sure somebody on here will.