unable to return global variable

[madkris]

hi, im new to php and was trying to do a sort on an array without using the predefined ones, everything else seems to be working except for this part..

was hoping you guys could help me out. thanks in advance..

 

<?php
$array1 = array(4,8,2,7,1);
$smallest;

//find smallest value in array
function findSmallest($array){
$size = count($array);
$GLOBALS['smallest'] = $array[0];
for($i = 0; $i < $size; $i++) {
	if($GLOBALS['smallest'] > $array[$i+1]){
		$GLOBALS['smallest'] = $array[$i+1];				
	}
	//echo $GLOBALS['smallest'] . "<br>";
}	
return $GLOBALS['smallest']; 					
}
findSmall($array1);
echo '<pre>';
	var_dump($GLOBALS['smallest']);//returns null
echo '</pre>';
?>

[Ken2k7]

ewww... $GLOBALS. I'll rewrite that without $GLOBALS.

 

<?php
$array1 = array(4,8,2,7,1);

//find smallest value in array
function findSmallest($array) {
     return empty($array)? false : min($array);              
}

$min = findSmallest($array1);
echo '<pre>';
var_dump($min);
echo '</pre>';

[taquitosensei]

You don't need to use $GLOBALS here. Just use a variable in your function then assign the result to a variable. And you function is findSmallest not findSmall.

$array1 = array(4,8,2,7,1);
$smallest;

//find smallest value in array
function findSmallest($array){
   $size = count($array);
   $smallest = $array[0];
   for($i = 0; $i < $size; $i++) {
      if($smallest > $array[$i+1]){
         $smallest = $array[$i+1];            
      }
     //echo $GLOBALS['smallest'] . "<br>";
   }   
   return $smallest;                
}
$smallest=findSmallest($array1); // or if you need to use $GLOBALS 
$GLOBALS['smallest']=findSmallest($array1); 
echo '<pre>';
      var_dump($smalles) // or 
      var_dump($GLOBALS['smallest']);
echo '</pre>';

[madkris]

ewww... $GLOBALS. I'll rewrite that without $GLOBALS.

sorry only way i could do it as of now, im still kinda confused with using passed by reference '&$variable'... your code looks great might give me a minute to trace thou..

 

And you function is findSmallest not findSmall.

 

sorry bout that, originally it was findSmall, changed it to findSmallest for readability and yes i have tried your approach too unfortunately when i do an echo or print_r on variable $smallest. it doesnt show anything. i made some comments on my code below. kindly read them to understand what ive figured out so far. thanks

 

$array1 = array(4,8,2,7,1);

function findSmallest($array){
   $size = count($array);
   $smallest = $array[0];
   for($i = 0; $i < $size; $i++) {
      if($smallest > $array[$i+1]){
         $smallest = $array[$i+1];            
      }
     //if i echo $smallest here it returns 4,2,2,1 respectively which means it should return value 1
   }   
   //if i do an echo here it doesnt show anything
   return $smallest;                
}

function mysort($array) {
        $smallest = findSmallest($array);
print_r($smallest); // doesnt show anything
}

mysort($array1);

[Ken2k7]

There's a problem with your method. What if $array is an empty array?

 

Try my function.

[madkris]

There's a problem with your method. What if $array is an empty array?

 

Try my function.

 

eureka! now im stuck with a new problem my while loop stops at 1st pass, any idea what im doing wrong?

 

<?php
$array1 = array(4,8,2,7,1);
$array2 = array();

//store smallest value into $array2
function getSmall($array, $key) {
	$temp = array_splice($array,$key,1); 
	foreach($temp as $value){
		$GLOBALS['array2'][] = $value;
	}
	$GLOBALS['array1'] = array_diff($GLOBALS['array1'],$GLOBALS['array2']);
}

//find the smallest value in $array1
function findSmallest($array) {
	return empty($array)? false : min($array);            
}

//get index of smallest value
function getSmallIndex($array, $small) {
	$key = array_search($small, $array); 
	return $key;
}

//sort
function mysort($array) {
	while(count($array) > 0) {
		$smallest = findSmallest($array);
		$key = getSmallIndex($array,$smallest);
		$array = getSmall($array,$key);			
	}
}
mysort($array1);

echo '<pre>array1:';
	var_dump($GLOBALS['array1']);
echo '</pre><br>';
echo '<pre>array2:';
			var_dump($GLOBALS['array2']);
echo '</pre>';
?>

[Ken2k7]

What are you trying to do? Sort the array? If so, there is the sort function.

 

<?php
$unsortedarray = $sortedarray = array(4,8,2,7,1);
sort($sortedarray);
var_dump($unsortedarray, $sortedarray);

[madkris]

What are you trying to do? Sort the array? If so, there is the sort function.

Yes, I am trying to sort the array without using the predefine sort functions in php.

 

Well now my while loop goes on an infinite loop. Any idea what I'm doing wrong?

 

	$array1 = array(4,8,2,7,1);
$array2 = array();

//store smallest value into $array2
function getSmall($array, $key) {
$temp2 = array_splice($array,$key,1); 
foreach($temp2 as $value){
	$GLOBALS['array2'][] = $value;
}
$temp1 = array_diff($GLOBALS['array1'],$GLOBALS['array2']);
$GLOBALS['array1'] = $temp1;
return $temp1;
}

//find the smallest value in $array1
function findSmallest($array) {
return empty($array)? false : min($array);            
}

//get index of smallest value
function getSmallIndex($array, $small) {
$key = array_search($small, $array); 
return $key;
}

//sort
function mysort($array) {
while(count($array) > 0) {
	$smallest = findSmallest($array);
	$key = getSmallIndex($array,$smallest);

	$array = getSmall($array,$key);

	echo '<pre>array1:';
		var_dump($GLOBALS['array1']);
	echo '</pre>';
	echo "<br>";
	echo '<pre>array2:';
		var_dump($GLOBALS['array2']);
	echo '</pre>';

}
}
mysort($array1);

 

here is the output before my browser crashes due to the infinite loop

5// array length before getSmall function inside my mysort function
4//array length after getSmall function inside my mysort function

array1:array(4) {
  [0]=>
  int(4)
  [1]=>
  int(
  [2]=>
  int(2)
  [3]=>
  int(7)
}


array2:array(1) {
  [0]=>
  int(1)
}

4
3

array1:array(3) {
  [0]=>
  int(4)
  [1]=>
  int(
  [3]=>
  int(7)
}


array2:array(2) {
  [0]=>
  int(1)
  [1]=>
  int(2)
}

3
2

array1:array(2) {
  [1]=>
  int(
  [3]=>
  int(7)
}


array2:array(3) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(4)
}

2
2

array1:array(2) {
  [1]=>
  int(
  [3]=>
  int(7)
}


array2:array(3) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(4)
}

2
2

array1:array(2) {
  [1]=>
  int(
  [3]=>
  int(7)
}


array2:array(3) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(4)
}

[madkris]

I was tracing my code and i found the problem, still trying to figure out why this part gets the value of zero thou. Ideas?

$array1 =  array(1=>8, 3=>7);
$array2 = array(0=>1,1=>2, 2=>4);

//same code as the one posted above..

$smallest = findSmallest($array1);
$key = getSmallIndex($array1,$smallest);
echo "key :<b>" . $key . "</b> smallest :<b>" . $smallest ."</b><br><br>";
$temp2 = array_splice($array1,$key,1); //evaluates to array(0) {} not sure why : array_splice($array1,$key,1) ==> array_splice($array1,3,1) ==> array_splice(array,offset,length)
echo '<pre>$array:';
var_dump($temp2);
echo '</pre><br>';	
foreach($temp2 as $value){
echo "$value :" . $value;
$GLOBALS['array2'][] = $value;
}

 

output:

key :3 smallest :7

$array:array(0) {
}

[madkris]

SOLVE!

 

thanks for the help guys..