how to make multidimensional arrays toss to javascript?

[hockey97]

Hi, I want to know how to make multidimensional arrays  and toss it to javascript.

 

here is my example. Lets say our website sells fruit.

 

I store fruit names and prices in a database.

 

I then have html code and javascript code to make a select html tag.

 

I need to take the names from the database and prices from the database.

 

I then need to populate the select tag.

 

yet with javascript  I need to  generate more then 1 select tags  with a use of a button.

 

that way the customer at check out can buy more then 1 fruit. So they are not limited to just 1 fruit to be bought at a time.

 

 

how can one do this?

[phpSensei]

Do you want to learn how to make the arrays themselves or how to process them in Javascript?

[hockey97]

I know how to make static arrays and multi-dimensional arrays.

 

I don't know exactly how I can grab  data from a database to generate the array to make a list.

 

then toss it from php to javascript. because I need to use javascript to generate more then 1 select tag.

 

based  from a button click.

 

so when you click this button it will make more select tags. Yet, have the same list.

 

like my example is a list of fruits... each select tag that been created will have these fruit names so the customer can select more then 1 fruit and can be different fruits as well.

 

I would say both.  like I never made an array using variables inside the array.

 

I only made a static array before where you do things by hand.

 

but I want to populate the array with what is stored in the database.

 

I hope this makes any sense.

[phpSensei]

You can pass PHP variables to Javascript.

 

<?php 
$array = array('1','2','3','4');
?>

<script>
testVar = '<?php print_r($array); ?>';

alert(testVar);
</script>

 

You won't be able to use a javascript loop to break down that array since its just a string, but what you can do is create a javascript ARRAY and put it inside a PHP LOOP and pass the database variables to it.

[hockey97]

how would you do that? I tried to do this just now but it's not working. I am getting a empty select tag.

 

how would I use variables inside the array  instead of hand writting the content?

[phpSensei]

Post your code and what you tried to do so far.

 

Thanks

[trq]

It's no different to outputting any html markup.

 

<?php

$a = array('foo' => 'bar', 'bob' => 'boo');
echo '<script>';
echo 'var a = [];';
foreach ($a as $k => $v) {
  echo "  a[$k] = $v;";
}
echo '</script>';

[hockey97]

here is my code:

 

error

 

it's javascript inside a php file. so you will see echo it's just because it's inside php.

 

I used a while loop. It generates the code.

[phpSensei]

edit: Refer to Thorpe's example.

[trq]

Your code will do nothing but produce an error

[phpSensei]

Heres what my code printed

 

<script>
testVar = 'Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
)
';
</script>

 

Just to show you OP how the PHP variable implemented inside Javascript. You just need to modify the quotations correctly, and the \n. Again Thorpe's example is the best one

 

see ... Alerts 'Array([0] => 1[1] => 2[2] => 3[3] => 4)'

<script>
testVar = " Array([0] => 1[1] => 2[2] => 3[3] => 4)";
</script>

[hockey97]

but then how do you use variables inside the arrays?

 

like all examples you showed where static arrays.. meaning you had to hand code it yourself.

 

how can you populate the array via variables?

[phpSensei]

Thorpe's example populates the var a with a supplied array from PHP.

 

<?php

$a = array('foo' => 'bar', 'bob' => 'boo');
echo '<script>';
echo 'var a = [];';
foreach ($a as $k => $v) {
  echo "  a[$k] = $v;";
}
echo '</script>';

 

[hockey97]

no, I am saying in that $a variable... if inside that array.. that bob and boo  if you replace them with variables... how  can you instead of directly writting the stuff... how can you populate the array.... like if I got fruit names in my database... how would you grab them from the database and then put thing inside an array?

[phpSensei]

Your not paying attention to the examples man. Just create a sql query, fetch the data and populate "a".

 

then in Javascript you have an array full of values from your database.

[hockey97]

so if be like this?

 

$result ---> this be what mysql spit out.

$a = array('foo' => $result);

 

that be how I assign or populate the array from a database?

[trq]

Assuming $result is the result of a call to mysql_query. No.

 

You would need to loop through that result.

 

<?php

$sql = "SELECT a, b FROM table;";
if ($result = mysql_query($sql)) {
    if (mysql_num_rows($result)) {
        echo '<script>';
        echo 'var a = [];';
        while ($row = mysql_fetch_assoc($result)) {
            echo "  a[{$row['a']}] = '{$row['b']}';"
        }   
        echo '</script>';
    };  
}