php往数组添加元素

<?php
$array = array("apple", "banana");
array_push($array, "orange", "grape");
print_r($array);
?>

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
    [3] => grape
)

<?php
$array = array("apple", "banana");
$array[] = "orange";
$array["fruit"] = "grape";
print_r($array);
?>

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
    [3] => grape
)

<?php
$array = array("apple" => "red", "banana" => "yellow");
if (!isset($array["orange"])) {
    $array["orange"] = "orange";
}
print_r($array);
?>

Array
(
    [apple] => red
    [banana] => yellow
    [orange] => orange
)