How to tell if class attribute is bool, int, etc.?

[kilbey1]

I am trying to document a class attribute in this format:
Attribute: Description (data type : default value)
How can you tell the data type of that attribute?

Example:
$displayTableHeader = TRUE;

So I want to know if this is int, bool, etc.:

$displayTableHeader = Creates table heading for display function tables (int: TRUE)
OR
$displayTableHeader = Creates table heading for display function tables (bool: TRUE)

Thanks!

[thorpe]

im not exactly sure what the question is, but true / false is a booleen.

[Weedpacket]

[man]is_bool[/man], [man]is_float[/man], [man]is_string[/man], [man]is_array[/man], [man]gettype[/man]....

[kilbey1]

thorpe:
That's basically what I needed. Ah, so if true/false is boolean, then the following would be:

0, 1, etc. = int
empty = string
true/false/ = bool
null = int
"some text", "" = string

So if I look at examples like:
var $displayDecimals = 2;
var $displayTotals = FALSE;
...then the first would be int, and the second would be boolean?

Is there ever a case that things are not what they appear, ie. empty is not always a string and null is always not int? Are there 'default' types for these?

weedpacket:
Thanks for those...I'm guessing it would be possible to build a small text field that would allow input of a variable ie.
var $displayDecimals = 2;
...with results is_bool = true, is_float = false, is_string = false, is_array = false. (I read that gettype should be avoided for checking data types.)

[thorpe]

null is null.

you might want to take a look at datatypes in the manual

[kilbey1]

Thanks for your help. I wanted to code up a small application to tell me if something is a certain type, so I put this together - but it's not accurate. For example, if I enter '$SMTP_PORT = 25;' into the text box in the below code, it always interprets as a string - or even if I enter just the number 25.

<?php

$entry = $HTTP_POST_VARS['expression'];

switch ($i) {
    case "submit":
        //echo $entry;
        if (is_int($entry)) {
           echo "This is an integer.";
        }
        if (is_string($entry)) {
           echo "This is a string.";
        }
        if (is_array($entry)) {
           echo "This is an array.";
        }
        if (is_float($entry)) {
           echo "This is a float.";
        }
        echo '<form action="'.$PHP_SELF.'?i=submit" method="POST" enctype="application/x-www-form-urlencoded"><input type="text" name="expression" value="'.$expression.'"/><input type="submit" value="Submit" /></form>';
        echo '<BR>';
        echo '';
       break;
    default:
        echo '<form action="'.$PHP_SELF.'?i=submit" method="POST" enctype="application/x-www-form-urlencoded"><input type="text" name="expression" value="'.$expression.'"/><input type="submit" value="Submit" /></form>';
}

?>

[ednark]

also remember that triple === also does type checking. so this might be a shortcut depending on what you are doing.

echo (1==true)  ? " (1==true)  -> true " : " (1==true)  -> false " ;
echo "<br />\n";
echo (1===true) ? " (1===true) -> true " : " (1===true) -> false " ;

result:
(1==true) -> true
(1===true) -> false

[ednark]

oh i see... everything coming across via the Request will be a string...

you might be thinking about using regular expressions

$string = $_POST['key'];
/// if there are only digits - assume 'int'
if ( preg_match('/^\d+$/',$string) ) {
    /// assume we have an int
}

/// if it is only the string TRUE or FALSE
if ( preg_match('/^(true|false)$/',$string) ) {
    /// assume we have a bool
}

is that more along the lines of what you were thinking?
is that

[kilbey1]

That works more like I wanted, thanks!

The way I have it now, it's always returned as a string in addition to 'boolean' and 'integer'. Is there a way I could narrow it down so that when I put in

$SMTP_PORT = "25";
or
$SMTP_PORT = 25;

it would tell me that "25" is a string and 25 is an integer?

This may answer my own question:
I'd have to use some function to check for the existence of =, and look at everything following the first occurence of that. Finding that, check for the existence of '', "" or not.

As for arrays, I suppose for that I could check for the existence of the word 'array' in a regexp.

<?php
$string = $_POST['expression'];

switch ($i) {
    case "submit":
        if ( preg_match('/^\d+$/',$string) ) {
            /// assume we have an int
            echo "this is an integer";
        }

    /// if it is only the string TRUE or FALSE
    if ( preg_match('/^(true|false)$/',$string) ) {
        /// assume we have a bool
        echo "this is boolean";
    }

    if (is_string($string)) {
       echo "This is a string.";
    }
    if (is_array($string)) {
       echo "This is an array.";
    }

    echo '<form action="'.$PHP_SELF.'?i=submit" method="POST" enctype="application/x-www-form-urlencoded"><input type="text" name="expression" value="'.$expression.'"/><input type="submit" value="Submit" /></form>';
    echo '<BR>';
    echo '';
   break;
default:
    echo '<form action="'.$PHP_SELF.'?i=submit" method="POST" enctype="application/x-www-form-urlencoded"><input type="text" name="expression" value="'.$expression.'"/><input type="submit" value="Submit" /></form>';
}

?>