PHP | Ds\Vector filter() Function

The Ds\Vector::filter() function is used to filter out the only elements which satisfy the condition defined in the callback function. After doing a filter on the vector, it will eliminate the elements which do not satisfy the condition mentioned in the function. Syntax:

Ds\Vector public Ds\Vector::filter( $callback )

Parameters: This function accepts single parameter $callback which returns true if the element in the vector is to be included, else return false. Return Value: This function returns the vector with all the elements which are filtered according to the callable function. Below programs illustrate the Ds\Vector::filter() function in PHP: Program 1: PHP

<?php

// Create new vector element
$vector = new \Ds\Vector([1, 2, 3, 4, 5]);

echo "Original Vector elements\n";

// Display the vector element
var_dump($vector);

echo("\nElements greater than or equal to 4\n");

// Filter the vector element
var_dump($vector->filter(function($value) {
    return $value >= 4;
}));

?>

Output:

Original Vector elements
object(Ds\Vector)#1 (5) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(3)
  [3]=>
  int(4)
  [4]=>
  int(5)
}

Elements greater than or equal to 4
object(Ds\Vector)#3 (2) {
  [0]=>
  int(4)
  [1]=>
  int(5)
}

Program 2: PHP

<?php

// Create new vector element
$vector = new \Ds\Vector([1, 2, 3, 4, 5]);

echo "Original Vector elements\n";

// Display the vector element
var_dump($vector);

echo("\nOdd elements\n");

// Use filter() function to filter
// the vector element
var_dump($vector->filter(function($value) {
    return $value % 2 == 1;
}));

?>

Output:

Original Vector elements
object(Ds\Vector)#1 (5) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(3)
  [3]=>
  int(4)
  [4]=>
  int(5)
}

Odd elements
object(Ds\Vector)#3 (3) {
  [0]=>
  int(1)
  [1]=>
  int(3)
  [2]=>
  int(5)
}

Reference: http://php.net/manual/en/ds-vector.filter.php