The `array_combine()` function in PHP takes two arrays as input and creates a new array, using one array as the keys and the other as the values. This function is available in PHP versions including 7.3.
Syntax:
<?php array_combine(array $keys, array $values): array ?>
$keys: An array of keys.
$values: An array of values.
Key Points:
1. Both the `$keys` and `$values` arrays must have the same number of elements.
2. If the `$keys` array contains duplicate values, the last value from the `$values` array will be used.
3. If the arrays are of unequal length, the function will return `false` and issue a warning.
Example:
<?php $keys = ["a", "b", "c"]; $values = [1, 2, 3]; $combined = array_combine($keys, $values); print_r($combined); ?>
Output:
<?php Array ( [a] => 1 [b] => 2 [c] => 3 ) ?>
In this example:
1. The `$keys` array has the values `[“a”, “b”, “c”]`.
2. The `$values` array has the values `[1, 2, 3]`.
3. The `array_combine()` function merges these two arrays into an associative array where each key from the `$keys` array corresponds to the value at the same index in the `$values` array.
Error Handling Example:
<?php
$keys = ["a", "b", "c"];
$values = [1, 2];
$combined = array_combine($keys, $values);
if ($combined === false) {
echo "The arrays must have the same number of elements.";
}
?>
Output:
<?php The arrays must have the same number of elements. ?>
In this case, the function returns `false` because the number of elements in the `$keys` array (3) is not equal to the number of elements in the `$values` array (2).