Merging two different tables using arrays

Question

I have two tables.

1) products : id,name,price

2) books : id,title,book_price

Now I want to merge the data of these two tables and sort them by lowest price using arrays.

How can I merge these two arrays ?

It should be something like this:

<?php
$a1=array( 
            "id"=>1,"name"=>'Ram',"price"=>100 ,
            "id"=>2,"name"=>'Keyboard',"price"=>200 ,
            "id"=>3,"name"=>'Mouse',"price"=>300 ,
            "id"=>4,"name"=>'LCD',"price"=>400 ,

            );


$a2=array( 
            "id"=>1,"title"=>'ABC',"book_price"=>150 ,
            "id"=>2,"title"=>'XYZ',"book_price"=>250 ,

            );


print_r(array_merge($a1,$a2));
?> 

Answer 1

$a2=array( 
            "id"=>1,"title"=>'Regions',"book_price"=>150 ,
            "id"=>2,"title"=>'Routes',"book_price"=>250 ,

            );

$a1=array( 
            "id"=>1,"name"=>'Ram',"price"=>100 ,
            "id"=>2,"name"=>'Keyboard',"price"=>200 ,
            "id"=>3,"name"=>'Mouse',"price"=>300 ,
            "id"=>4,"name"=>'LCD',"price"=>400 ,

            ); +a2

or,

$output = $a1 + $a2;