I trying get another variable in php, from existing text but I have issue to do this.
When I echo $address_number; I get list3.
So I need to get variable $list3 and I need echo $list3; after that.
Something like
<?php echo $(echo $address_number;); ?>
But this is not possible. Any solutions?
Solution:
$address_number = $address.$number;
$iframe_url ="$address_number";
<?php echo $$iframe_url; ?>
Thanks everybody!
Use variables variables and the way they work is like so
$adress_number = "list3";
$list3 = "some value";
echo $$address_number;
the above code will output 'some value', what it's doing is using the value of the variable $address_number and treating it as a variable name, so it will look for that variable name and print it's value
Related
Is it possible to achieve something like this?
$_SESSION["new"] = "This are the values of $_SESSION['A'] & $_SESSION['B']";
I want to echo the "new" session value on a different page for my user to check.
I tried various things such as the code below but it doesn't work.
$_SESSION["new"] = <?php echo $_SESSION['A']?>;
Yes, you can assign multiple session variables by using the concatenation operator.
$_SESSION["new"] = "This are the values of ".$_SESSION['A']."&".$_SESSION['B'];
On the page, you want to display, simply print the session variable.
echo $_SESSION["new"];
Please make sure,on both pages, you are using session_start() function
$_SESSION["new"] = 'foo bar';
You can simply assign any value to your session variables. you can read more here
if you are sure of the type of value in $_SESSION["A"] and $_SESSION["B"], and assuming in your case they are both string, you can do the following:
$_SESSION["new"] = sprintf('This are the values of %s & %s', $_SESSION['A'], $_SESSION['B']);
I have a simple PHP file with the following:
<?php
echo 'catid=$_GET["catid"]';
<?>
When I run the page, the output is:
catid=$_GET["catid"]
I'm accessing the page as www.abc.com/temp.php?catid=3. I'd like $_GET to execute so I see:
catid=3
What am I doing wrong?
You have to cancat the two:
echo 'catid=' . $_GET["catid"];
or you could use " (double quotes):
echo "catId=$someVar";
$_Get is a variable, and to echo a variable you do not need parenthesis around it.
<?php
echo 'catid='.$_GET["catid"];
?>
please see this : source
You can use non-array variables for that:
$getCatID = $_GET["catid"];
echo "catid=$getCatID";
Or you can use (recommended):
echo 'catid=' . $_GET["catid"];
You may try:
echo "catid= {$_GET['catid']}";
The best way to use variables in string is:
echo "catid={$_GET['catid']}";
You have to use double quoted string to notify PHP that it might contains variables inside. $_GET is array, so you will need to put the variable statement in {}.
<?php
echo "catid={$_GET['catid']}";
?>
There are a few options to combine a variable with a string.
<?php
$var = "something";
// prints some something
echo 'some ' . $var; // I prefer to go for this one
// prints some something
echo "some $var";
// prints some $var
echo 'some $var';
// prints some something
echo "some {$var}";
?>
The title may be a little confusing. This is my problem:
I know you can hold a variable name in another variable and then read the content of the first variable. This is what I mean:
$variable = "hello"
$variableholder = 'variable'
echo $$variableholder;
That would print: "hello". Now, I've got a problem with this:
$somearray = array("name"=>"hello");
$variableholder = "somearray['name']"; //or $variableholder = 'somearray[\'name\']';
echo $$variableholder;
That gives me a PHP error (it says $somearray['name'] is an undefined variable). Can you tell me if this is possible and I'm doing something wrong; or this if this is plain impossible, can you give me another solution to do something similar?
Thanks in advance.
For the moment, I could only think of something like this:
<?php
// literal are simple
$literal = "Hello";
$vv = "literal";
echo $$vv . "\n";
// prints "Hello"
// for containers it's not so simple anymore
$container = array("Hello" => "World");
$vv = "container";
$reniatnoc = $$vv;
echo $reniatnoc["Hello"] . "\n";
// prints "World"
?>
The problem here is that (quoting from php: access array value on the fly):
the Grammar of the PHP language only allows subscript notation on the end of variable expressions and not expressions in general, which is how it works in most other languages.
Would PHP allow the subscript notation anywhere, one could write this more dense as
echo $$vv["Hello"]
Side note: I guess using variable variables isn't that sane to use in production.
How about this? (NOTE: variable variables are as bad as goto)
$variablename = 'array';
$key = 'index';
echo $$variablename[$key];
How can I do that?
I have something like:
define($stuff.'_FOO', 'whatever');
echo $stuff.'_FOO';
and it doesn't work :(
I just want to echo the constant's value...
Check out constant().
In your case:
echo constant($stuff . '_FOO');
First make a constant:
define("FOO_BAR", "something more");
then you can get the value by using constant():
echo constant("FOO_BAR");
Read more about constants in the manual.
How does php handle something like this...
$blah = "Testing a variable";
$$blah = "test";
What would my new variable name be?
Everything you need to know about variable variables at http://www.php.net/manual/en/language.variables.variable.php, except for one thing: don't use them.
echo ${'Testing a variable'};
However, you don't want to do this in practice. It makes for unmaintainable, bug-prone code.
The variable $blah must contain a valid variable name.
This will tell you about variables: http://www.php.net/manual/en/language.variables.basics.php
Not really an answer, but...
<?php
function I_love_you()
{
return "haha";
}
$haha = "HoHoHo";
$tom = "I_love_you";
$blah = "tom";
echo ${$$blah()};
?>