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up vote 0 down vote favorite 

$string = "id";

want result to be like 

$id = "new value";

how to code in php

thank you.

Edit..

thank you for fast answer. how about this.


$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";

thank you.

share|improve this question
Although PHP does allow you to do this (as the answers below show), it generally considered a bad design principle and it makes your code a lot harder to maintain. A better approach is probably to use an associative array, for example $my_array['id'] = "new value"; – Gareth Jan 11 '11 at 10:47
1  
You will have to create a seperate question for the update. – RobertPitt Jan 11 '11 at 11:41

7 Answers

up vote 0 down vote accepted

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!

share|improve this answer
what if instead of define variable id,name,value manually, want to take it from $column array. I hope you under stand my point why I define $column array. – Paisal Jan 11 '11 at 11:36
@Paisal I have updated my answer to create the column name variables dynamically. Bear in mind what @Marco Mariani said about the code being hard to read – Alan Whitelaw Jan 11 '11 at 12:28
up vote 2 down vote

You are looking for Variable Variables

$$string = "new value";

will let you call 

echo $id; // new value

Later in your script

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up vote 2 down vote

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"};
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thank you i have new question (edit above) – Paisal Jan 11 '11 at 10:59
up vote 1 down vote

You can do this

$$string = "new value";

juste double $

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up vote 0 down vote

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".

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up vote 0 down vote

Don't do that. Just use an array.

$arr[$string] = 'new value';

ref: How do I build a dynamic variable with PHP?

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Don't do variable variables? What's your reasoning for this, if you don't mind me asking? – Alan Whitelaw Jan 11 '11 at 10:50
it's dirty, unmaintainable, namespace-polluting code. – Marco Mariani Jan 11 '11 at 10:52
up vote 0 down vote

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++;
  }
}
share|improve this answer

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