PHP | Ds\Vector map() Function

The Ds\Vector::map() function is an inbuilt function in PHP which is used to return the result of a callback after applying to each value in the vector.

Syntax:

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

Parameters: This function accepts single parameter $callback which is to be applied to each vector elements.

Return Value: This function returns the vector after applying the callback to each value in the vector.

Below programs illustrate the Ds\Vector::map() function in PHP:

Program 1:

<?php

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

// Display the Vector element after
// applying the callback function
print_r($vector->map(function($value) {
    return $value * 10;
}));

?>

Output:

Ds\Vector Object
(
    [0] => 10
    [1] => 20
    [2] => 30
    [3] => 40
    [4] => 50
)

Program 2:This program shows the implementation of map() function which sets 1 in the vector for each element satisfying the condition in callback.

<?php

// Create new Vector
$vector = new \Ds\Vector([10, 20, 30, 40, 50]);

// Display the Vector element after
// applying the callback function
print_r($vector->map(function($value) {
    return $value <= 30;
}));

?>

Output:

Ds\Vector Object
(
    [0] => 1
    [1] => 1
    [2] => 1
    [3] => 
    [4] => 
)

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