php string name as variable - php

Question

$string = "id";
want result to be like
$id = "new value";
How do I code this in php?
Edit..
How about the below?
$column = array("id","name","value");
let say found 3 row from mysql
want result to be like this
$id[0] = "3";
$id[1] = "6";
$id[2] = "10";
$name[0] = "a";
$name[1] = "b";
$name[2] = "c";
$value[0] = "bat";
$value[1] = "rat";
$value[2] = "cat";

Answer 1

Theres 2 main methods
The first is the double $ (Variable Variable) like so
$var = "hello";
$$var = "world";
echo $hello; //world
//You can even add more Dollar Signs
$Bar = "a";
$Foo = "Bar";
$World = "Foo";
$Hello = "World";
$a = "Hello";
$a; //Returns Hello
$$a; //Returns World
$$$a; //Returns Foo
$$$$a; //Returns Bar
$$$$$a; //Returns a
$$$$$$a; //Returns Hello
$$$$$$$a; //Returns World
//... and so on ...//
#source
And the second method is to use the {} lik so
$var = "hello";
${$var} = "world";
echo $hello;
You can also do:
${"this is a test"} = "works";
echo ${"this is a test"}; //Works
I had a play about with this on streamline objects a few weeks back and got some interesting results
$Database->Select->{"user id"}->From->Users->Where->User_id($id)->And->{"something > 23"};

Answer 2

You are looking for Variable Variables
$$string = "new value";
will let you call
echo $id; // new value
Later in your script

Answer 3

Second answer in response to your edit:
$result = mysql_query($sql);
$num = mysql_num_rows($result);
$i = 0;
$id = array();
$name = array();
$value = array();
if ($num > 0) {
while ($row = mysql_fetch_assoc($result)) {
$id[$i] = $row['id'];
$name[$i] = $row['name'];
$value[$i] = $row['value'];
$i++;
}
}
This loops around your result, using the counter $i as the key for your result arrays.
EDIT
Additional answer in response to your comment:
while ($row = mysql_fetch_assoc($result)) {
foreach($row as $column_name => $column_value) {
$temp_array[$column_name][$i] = $column_value;
}
$i++;
}
foreach ($temp_array as $name => $answer) {
$$name = $answer;
}
This code creates a temporary multidimensional array to hold the column names and values the loops around that array to create your variable variable arrays. As a side not I had to use the temp array as $$column_name[$i] doesn't work, I would love to see alternative answers to this problem.
Final note #Paisal, I see you have never accepted an answer, I wouldn't have put this much effort in if I had seen that before!

Answer 4

You can do this
$$string = "new value";
juste double $

Answer 5

Are you referring to variable variables?
That would accomplish something like this:
$string = "id";
$$string = "new value";
This produces a variable $id with the value "new value".

Answer 6

Don't do that. Just use an array.
$arr[$string] = 'new value';
ref: How do I build a dynamic variable with PHP?

Answer 7

Try this :
$result = mysql_query($sql);
$num_rows = mysql_num_rows($result);
$i = 0;
if ($num_rows) {
while ($row = mysql_fetch_assoc($result)) {
foreach($row AS $key => $value) {
${$key}[$i] = $value;
}
$i++;
}
}

Answer 8

For those of us who need things explained in great detail...
// Creates a variable named '$String_Variable' and fills it with the string value 'id'
$String_Variable = 'id';
// Converts the string contents of '$String_Variable', which is 'id',
// to the variable '$id', and fills it with the string 'TEST'
$$String_Variable = 'TEST';
// Outputs: TEST
echo $id;
// Now you have created a variable named '$id' from the string of '$String_Variable'
// Essentially: $id = 'Test';