Asked  2 Years ago    Answers:  5   Viewed   57 times

I have a PHP array as follows:

$messages = [312, 401, 1599, 3, ...];

I want to delete the element containing the value $del_val (for example, $del_val=401), but I don't know its key. This might help: each value can only be there once.

I'm looking for the simplest function to perform this task, please.

 Answers

1

Using array_search() and unset, try the following:

if (($key = array_search($del_val, $messages)) !== false) {
    unset($messages[$key]);
}

array_search() returns the key of the element it finds, which can be used to remove that element from the original array using unset(). It will return FALSE on failure, however it can return a false-y value on success (your key may be 0 for example), which is why the strict comparison !== operator is used.

The if() statement will check whether array_search() returned a value, and will only perform an action if it did.

Saturday, September 17, 2022
5

When you set cell values individually, you have the option of setting the datatype explicitly, but when you use the fromArray() method, you don't have this option.

However, by default, PHP uses a default value binder to identify datatypes from the values passed, and set the cell datatype accordingly. This default behaviour is defined in a class /PHPExcel/Cell/DefaultValueBinder.php.

So you can create your own value binder, as described in the PHPExcel Documentation, that would set every value as a string datatype.

Something like:

class PHPExcel_Cell_MyColumnValueBinder extends PHPExcel_Cell_DefaultValueBinder implements PHPExcel_Cell_IValueBinder
{
    protected $stringColumns = [];

    public function __construct(array $stringColumnList = []) {
        // Accept a list of columns that will always be set as strings
        $this->stringColumns = $stringColumnList;
    }

    public function bindValue(PHPExcel_Cell $cell, $value = null)
    {
        // If the cell is one of our columns to set as a string...
        if (in_array($cell->getColumn(), $this->stringColumns)) {
            // ... then we cast it to a string and explicitly set it as a string
            $cell->setValueExplicit((string) $value, PHPExcel_Cell_DataType::TYPE_STRING);
            return true;
        }
        // Otherwise, use the default behaviour
        return parent::bindValue($cell, $value);
    }
}

// Instantiate our custom binder, with a list of columns, and tell PHPExcel to use it
PHPExcel_Cell::setValueBinder(new PHPExcel_Cell_MyColumnValueBinder(['A', 'B', 'C', 'E', 'F']));

$objPHPExcel = new PHPExcel();
$objPHPExcel->getActiveSheet()->fromArray($dataArray,null,"A2");
Wednesday, August 17, 2022
 
1

The second usort overrides the output of the first usort.

What you need to do is merge the 2 sorting functions to order themselves by title and then date time.

Pseudocode would be :

function SortByTitleAndDateTime($a,$b)
    1) SortByTitle and return the value if it is non zero.
    2) If SortByTitle is zero (meaning the 2 values are the same in terms of title), 
        do SortByDateTime

In the end, you'd only need to call usort(array, SortByTitleAndDateTime).

Wednesday, December 21, 2022
 
mvg
 
mvg
2

There's a lot been written about PHPExcel and memory use, and I'm not going to repeat it all here.

Try reading some of the threads on the PHPExcel discussion board discussing the issue, such as this one; or previous answers here on SO such as this one or this one

Wednesday, October 19, 2022
 
inutan
 
1

You can take advantage of the fact that PHP will dereference the results of a function call.

Here's some example code I whipped up:

$x = 'x';
$y = 'y';
$arr = array(&$x,&$y);
print_r($arr);

echo "<br/>";
$arr2 = $arr;
$arr2[0] = 'zzz';
print_r($arr);
print_r($arr2);

echo "<br/>";
$arr2 = array_flip(array_flip($arr));
$arr2[0] = '123';
print_r($arr);
print_r($arr2);

The results look like this:

Array ( [0] => x [1] => y )
Array ( [0] => zzz [1] => y ) Array ( [0] => zzz [1] => y )
Array ( [0] => zzz [1] => y ) Array ( [0] => 123 [1] => y ) 

You can see that the results of using array_flip() during the assigment of $arr to $arr2 results in differences in the subsequent changes to $arr2, as the array_flip() calls forces a dereference.

It doesn't seem terribly efficient, but it might work for you if $this->x->getResults() is returning an array:

$data['x'] = array_flip(array_flip($this->x->getResults()));
$data['y'] = $data['x'];

See this (unanswered) thread for another example.

If everything in your returned array is an object however, then the only way to copy an object is to use clone(), and you would have to iterate through $data['x'] and clone each element into $data['y'].

Example:

$data['x'] = $this->x->getResults();
$data['y'] = array();
foreach($data['x'] as $key => $obj) {
    $data['y'][$key] = clone $obj;
}
Wednesday, September 7, 2022
Only authorized users can answer the search term. Please sign in first, or register a free account.
Not the answer you're looking for? Browse other questions tagged :
 

Browse Other Code Languages