PHP SplFixedArray key() Function

The SplFixedArray::key() function is an inbuilt function in PHP which is used to get the key of the current index of the array.

Syntax:

int SplFixedArray::key()

Parameters: This function does not accept any parameter.

Return Value: This function returns the key of the current index of the array.

Below programs illustrate the SplFixedArray::key() function in PHP:

Program 1:

<?php

// Create a fixed size array
$gfg = new SplFixedArray(6);

$gfg[0] = 1;
$gfg[1] = 5;
$gfg[2] = 1;

$gfg->next();
$gfg->next();

// Print key of current position
echo $gfg->key() . "\n";
?>

Output:

2

Program 2:

<?php

// Create some fixed size array
$gfg = new SplFixedArray(6);

$gfg[0] = 1;
$gfg[1] = 5;
$gfg[2] = 1;
$gfg[3] = 11;
$gfg[4] = 15;
$gfg[5] = 17;

// Iterate array and print values
while($gfg->valid()) {

    // Print Key of each Index
    echo $gfg->key(). "\n";
    $gfg->next();
}
?>

Output:

0
1
2
3
4
5

Reference: https://www.php.net/manual/en/splfixedarray.key.php