Help...trying to build an array from a filtered array to build the page fast.

[sptrsn]

Instead of breaking down and actually learning how to use ajax, I'm thinking about trying to do something so I don't need a page refresh every time, and the filtered data is nearly instant. I just use the session array var, and build a new array from the rows that meet the conditions.

 

I'm thinking of loading a two dimensional array into a session var, then use some input buttons, and use the post vars to filter the array based on a set of predefined conditions. ie status = 0, status = 1. It's a fairly small number of conditions applied to two different fields.

 

So, I need to access specific fields within a row, and essentially create a new array either including or excluding that row depending on whether it met the condition.

 

I'm struggling on several parts.

1. not sure how to build the array so that I can access specific fields, then not sure how to access those fields.

Do I do this..... to build the array? ....

while($row = mysql_fetch_assoc($result)){
   $array[] = array($row['field1'], $row['field2']);
}

 

I was thinking about using a foreach and is_array() to get to each row...

foreach($array as $key => $value){
   if(is_array){
      foreach($value as $k => $v){
         if($v[0] == 1){  //stuck here $v[0] is not a field, it's the first char of the string. not sure how to access a field
            $new_array[] = $value;  //stuck here. I need to put the whole row back into the array if the condition was true. seems like I would have to use the field selectors and rebuild the array. 
         }
      }
  }

}

 

 

What would you do? Open to any ideas.

[freelance84]

   $array[] = array($row['field1'], $row['field2']);

That should work fine, it will create a new numeric key with the value being the array. And as long as the $row is returning what you expecting...

---

 

 

 

If the array called $array is only ever built via the method above then the $value in the first foreach will always be an array, so you don't need the is_array there. However you have not sent anything to the is_array, and could better look if you needed to use it:

foreach($array as $key => $value)
	{
   		if(is_array($value))
   			{
   				foreach($value as $k => $v)
   					{
   						if($v[0] == 1)
   							{  //stuck here $v[0] is not a field, it's the first char of the string. not sure how to access a field
   								$new_array[] = $value;  //stuck here. I need to put the whole row back into the array if the condition was true. seems like I would have to use the field selectors and rebuild the array. 
   							}
   					}
   			}
   	}

 

 

After this you then have a nested foreach which is not really needed. Again if your array is only built in the fashion as stated at the beginning the array in $value will only ever have 2 parts to it so you don't need a foreach and could just use something like this:

foreach($array as $key => $value)
	{
		if($value[0] == 1)
			{
				$new_array[] = $value;  //stuck here. I need to put the whole row back into the array if the condition was true. seems like I would have to use the field selectors and rebuild the array. 
			}
	}

 

Now to deal with the value you want to keep, simply push into a new array that you wish to keep:

//declaring your new array to keep
$new_array = array();

//filtering through the $array
foreach($array as $key => $value)
	{
		if($value[0] == 1)
			{
				$new_array[] = $value; 
			}
	}

 

 

And last but not least... the use of a foreach...  Maniac Dan once posted on a thread of mine a while ago about the use of the function foreach and how is saps memory as it essentially make a duplicate copy before working: http://sldn.softlayer.com/blog/dmcaloon/PHP-Memory-Management-Foreach

 

I don't know how big your $array will be but to optimize it further as the $array is simply a numeric one:

for ( $p = 0; $p < count($array); $p++ ) {
   		if($array[$p][0] == 1)
			{
				$new_array[] = $value; 
			}
}

 

And if you change at a later date to using an associative array for the $array then use this method as illustrated by maniac dan to loop through an associative without the use of a foreach:

http://www.phpfreaks.com/forums/index.php?topic=344015.msg1624048#msg1624048

 

[freelance84]

 

Oh and on your op the following:

 

 

I was thinking about using a foreach and is_array() to get to each row...

foreach($array as $key => $value){
   if(is_array){
      foreach($value as $k => $v){
         if($v[0] == 1){  //stuck here $v[0] is not a field, it's the first char of the string. not sure how to access a field
            $new_array[] = $value;  //stuck here. I need to put the whole row back into the array if the condition was true. seems like I would have to use the field selectors and rebuild the array. 
         }
      }
  }

}

 

Didnt work because $v is not an array. $v is the value of the the nested array:

foreach($array as $key => $value){
    if(is_array){
       foreach($value as $k => $v){

//you are now cycling through the array which is $value. The first time through $v is $row['field1'] and the second $v is $row['field2']

          if($v[0] == 1){  
             $new_array[] = $value;  
          }
       }
   }
}

 

However read the top thread as it solves all all of this i hope

 

[sptrsn]

This is great. Thank you for your input. I'm going to take another crack at this.