从input所给的数组中随机 选取一个或多个键
array_replace() 函数使用后面数组元素相同 key 的值替换 array1 数组的值。
$arr1 = array('hobby' => 'basketball');
$arr2 = array('hobby' => 'football');
$arr = array_replace($arr1, $arr2);
//$arr结果,array('hobby' => 'football');
$arr1 = array('hobby' => 'basketball');
$arr2 = array('sex' => 'male');
$arr = array_replace($arr1, $arr2);
//$arr结果,array('hobby' => 'basketball', 'sex' => 'male');
$arr1 = array('hobby' => array('a' => 'football', 'b' => 'basketball'));
$arr2 = array('hobby' => array('a' = > 'ping-pong'));
$arr = array_replace($arr1, $arr2);
//结果:array('hobby' => array('a' = > 'ping-pong'));
如果是递归的,结果:array('hobby' => array('a' => 'ping-pong', 'b' => 'basketball'));
将数组中的内容倒转
<?php
$array = array('a'=>'a',1,2);
/*
结果:
Array
(
[a] => a
[0] => 1
[1] => 2
)
*/
$revArray = array_reverse($araay);
print_r($revArray);
/*
结果:
Array
(
[0] => 2
[1] => 1
[a] => a
)
*/
$revArray = array_reverse($araay, true);
print_r($revArray);
/*
结果:
Array
(
[1] => 2
[0] => 1
[a] => a
)
*/
计算,参数数组值的总和
$arr = array(1, 2, 3, '4a', 2);
$sum = array_sum($arr);//结果: 12
将值排序完成后,会是一个索引数组,即便原来是一个关联数组
<?php
$fruits = array("lemon", "orange", "banana", "apple");
sort($arr);
//$arr: Array ( [0] => apple [1] => banana [2] => lemon [3] => orange )
$num = array('2', '11', '1', '21');
sort($num, SORT_NUMERIC);
//$num: Array ( [0] => 1 [1] => 2 [2] => 11 [3] => 21 )
假设实现以下排序 1----第一章 11---第一章第一节 2----第二章 21---第二章第一节
$num = array('2', '11', '1', '21');
sort($num, SORT_STRING);
//$num: Array ( [0] => 1 [1] => 11 [2] => 2 [3] => 21 )
判断指定值是否在一个数组里
别名 implode() 将一个数组转化字符串
如果是关联数组键是不会保留的
<?php
$arr = array('a'=>1, 'b'=>2);
echo join(',', $arr);
// 输出: 1,2