I have the following php variables in my code:
$masonry_item_width;
$masonry_item_padding;
I am trying to create a value for a new variable by doing soe maths with these two. Here is what I've written:
$skizzar_double_width_size = eval(
'return'.($masonry_item_width*2)+$masonry_item_padding.';'
);
However, this returns nothing when I echo out $skizzar_double_width_size
I've never done maths with php variables before, is there something i'm doing obviously wrong?
Try simply with this:
$skizzar_double_width_size = $masonry_item_width*2 +$masonry_item_padding;
To echo it out to HTML just write:
echo $skizzar_double_width_size;
And yes, it's that simple! :)
You don't have to use eval() just use this:
echo $skizzar_double_width_size = $masonry_item_width * 2 + $masonry_item_padding;
BTW: eval() === evil(), i have never seen a situation where you need eval() it just makes you problems
Related
Im a student studying PHP, Java. but I don't know if eval can access outside variable.
My code :
<?php
$o = "This is just test character";
$code = "echo $o;"
eval($code);
?>
does it active? if not, how can i make it to active? (my purpose is eval() can access outside variable..)
sorry for my bad english and thx for listening.
Apart from the obvious missing ; on line 2
The issue you're having with eval is the string you're passing is not valid PHP.
<?php
$o = "This is just test character";
$code = '<?php echo $o;';
eval('?>'.$code);
https://3v4l.org/CHkR3
And if you're using double quotes it will parse into the string and again create invalid PHP by missing the quotes.
<?php
$o = "This is just test character";
$code = "<?php echo '$o';";
eval('?>'.$code);
https://3v4l.org/CHkR3
Bottom line, if you don't know how eval works then you should definitely not use it.
You need to put the string in the $code variable between aposthropes and then it'll work. Like this:
$o = "'This is just test character'";
$code = "echo $o;";
eval($code);
I have this code for scraping team names from a table
$url = 'http://fantasy.premierleague.com/my-leagues/303/standings/';
$html = #file_get_html($url);
//Cut out the table
$FullTable = $html->find('table[class=ismStandingsTable]',0);
//get the text from the 3rd cell in the row
$teamname = $FullTable->find('td',2)->innertext;
echo $teamname;
This much works.. and gives this output....
Why Always Me?
But when I add these lines..
$teamdetails = $teamname->find('a')->href;
echo $teamdetails;
I get completely blank output.
Any idea why? I am trying to get the /entry/110291/event-history/33/ as one variable, and the Why Always Me? as another.
Instead do this:
$tdhtml = DOMDocument::loadHTML($teamdetails);
$link = $tdhtml->getElementsByTagName('a');
$url = $link->item(0)->attributes->getNamedItem('href')->nodeValue;
$teamdetails = $teamname->find('a')->href;
^^^^^^^^^---- never defined in your code
I also fail to see how your "works" code could possibly work. You don't define $teamname in there either, so all you'd never get is the output of a null/undefined variable, which is...no output all.
Marc B is right, I get that you don't have to initialize a variable, but he is saying you are trying to access a property of said variable:
$teamdetails = $teamname->find('a')->href;
^^^^^^^^^---- never defined in your code
This is essentially:
$teamname = null;
$teamname->find('a')->href;
The problem in your example is that $teamname is a string and you're treating it like a simple_html_dom_node
I know this may sound similar to some past Q/As, I think mine is slightly different though.. I have a webpage which I want to dynamically load text file information. I upload the text file through an iframe and I want to save this information from php to Javascript. Whenever I try to save this as a regular variable it doesn't work so I have tried to do this by saving this information as a part of the $_POST array under a hidden form named $_POST['hidden_form']. Whenever I try to read the php into Javascript, I keep getting an error "Unexpected token ILLEGAL." I have tried the following two codes:
for($i=0;$i< count($_POST['hidden_form']) ;$i++)
{
echo "saved_form[$i]='" . $_POST['hidden_form'][$i]. "';\n";
}
and
saved_form = <?php echo json_encode($_POST['hidden_form']); ?>;
Assigning a php array into a javascript array
I think the error has to do with the " ' " needed to specify the array but not sure. I have no idea where to go from here so any help would be GREATLY appreciated. If there are better methods to do this please let me know. Thanks in advance!
saved_form = '<?php echo addslashes(json_encode($_POST['hidden_form'])); ?>';
Or
for($i=0;$i< count($_POST['hidden_form']) ;$i++)
{
echo "saved_form[$i]='" . addslashes($_POST['hidden_form'][$i]) . "';\n";
}
Both should work, probably had quotes breaking something?
the best way i have used is,
text/javascript
var saved_form = <?php echo json_encode($_POST['hidden_form']) ?>
Please note there are no Quotes around the php so your saved_form is an Object not a string json string witch would require you to to use var form_object = eval(saved_form)
#Lee might have meant this?
Just a note though i would not use the Raw $_POST pass it to a function that can loop though and addSlashes every value inside the post some thing like
<?php
function arr_addSlashes($array){
$ret = array();
foreach($array as $k => $v){
$ret[$k] = addSlashes($v);
}
return $ret;
}
?>
I would like to know if there is a way to bind PHP function inside a regexp.
Example:
$path_str = '/basket.php?nocache={rand(0,10000)}';
$pattern = ? // something i have no idea
$replacement = ? // something i have no idea
$path = preg_replace($pattern, $replacement, $path_str);
Then :
echo "'$path'";
would produce something like
'/basket.php?nocache=123'
A expression not limited to the 'rand' function would be even more appreciated.
Thanks
You could do the following. Strip out the stuff in between the {} and then run an eval on it and set it to a variable. Then use the new variable. Ex:
$str = "/basket.php?nocache={rand(0,10000)}";
$thing = "rand(0,10000)";
eval("\$test = $thing;");
echo $test;
$thing would be what's in the {} which a simple substr can give you. $test the becomes the value of executing $thing. When you echo test, you get a random number.
Don't, whatever you do, store PHP logic in a string. You'll end up having to use eval(), and if your server doesn't shoot you for it, your colleagues will.
Anywhoo, down to business.
Your case is rather simple, where you need to append a value to the end of a string. Something like this would be sufficient
$stored = '/basket.php?nocache=';
$path = $stored . rand(0,10000);
If, however, you need to place a value somewhere in the middle of a string, or possibly in a variable location, you could have a look at sprintf()
$stored = '/basket.php?nocache=%d&foo=bar';
$path = sprintf($stored, rand(0,10000));
I would not try to store functions in a database. Rather store some kind of field that represents the type of function to use for each particular case.
Then inside your crontab you can do something like:
switch ($function)
{
case 'rand':
$path_str = '/basket.php?nocache='. rand(0,10000);
}
e.t.c
I would like to know if it's possible to execute the php code in a string. I mean if I have:
$string = If i say <?php echo 'lala';?> I wanna get "<?php echo 'dada'; ?>";
Does anybody knows how?
[EDIT] It looks like nobody understood. I wanna save a string like
$string = If i say <?php count(array('lala'));?>
in a database and then render it. I can do it using
function render_php($string){
ob_start();
eval('?>' . $string);
$string = ob_get_contents();
ob_end_clean();
return $string;
}
The problem is that I does not reconize php code into "" (quotes) like
I say "<?php echo 'dada'; ?>"
$string = ($test === TRUE) ? 'lala' : 'falala';
There are lots of ways to do what it looks like you're trying to do (if I'm reading what you wrote correctly). The above is a ternary. If the condition evaluates to true then $string will be set to 'lala' else set to 'falala'.
If you're literally asking what you wrote, then use the eval() function. It takes a passed string and executes it as if it were php code. Don't include the <?php ?> tags.
function dropAllTables() {
// drop all tables in db
}
$string = 'dropAllTables();';
eval($string); // will execute the dropAllTables() function
[edit]
You can use the following regular expression to find all the php code:
preg_match_all('/(<\?php )(.+?)( \?>)/', $string, $php_code, PREG_OFFSET_CAPTURE);
$php_code will be an array where $php_code[0] will return an array of all the matches with the code + <?php ?> tags. $php_code[2] will be an array with just the code to execute.
So,
$string = "array has <?php count(array('lala')); ?> 1 member <?php count(array('falala')); ?>";
preg_match_all('/(<\?php )(.+?)( \?>)/', $string, $php_code, PREG_OFFSET_CAPTURE);
echo $php_code[0][0][0]; // <?php count(array('lala')); ?>
echo $php_code[2][0][0]; // count(array('lala'));
This should be helpful for what you want to do.
Looks like you are trying to concatenate. Use the concatenation operator "."
$string = "if i say " . $lala . " I wanna get " . $dada;
or
$string = "if i say {$lala} I wanna get {$dada}.";
That is what I get since your string looks to be a php variable.
EDIT:
<?php ?> is used when you want to tell the PHP interpreter that the code in those brackets should be interpreted as PHP. When working within those PHP brackets you do not need to include them again. So as you would just do this:
// You create a string:
$myString = "This is my string.";
// You decide you want to add something to it.
$myString .= getMyNameFunction(); // not $myString .= <?php getMyNameFunction() ?>;
The string is created, then the results of getMyNameFunction() are appended to it. Now if you declared the $myString variable at the top of your page, and wanted to use it later you would do this:
<span id="myString"><?php echo $myString; ?></span>
This would tell the interpreter to add the contents of the $myString variable between the tags.
Use token_get_all() on the string, then look for a T_OPEN_TAG token, start copying from there, look for a T_CLOSE_TAG token and stop there. The string between the token next to T_OPEN_TAG and until the token right before T_CLOSE_TAG is your PHP code.
This is fast and cannot fail, since it uses PHP's tokenizer to parse the string. You will always find the bits of PHP code inside the string, even if the string contains comments or other strings which might contain ?> or any other related substrings that will confuse regular expressions or a hand-written, slow, pure PHP parser.
I would consider not storing your PHP code blocks in a database and evaluating them using eval. There is usually a better solution. Read about Design Pattern, OOP, Polymorphism.
You could use the eval() function.