【细说PHP学习】第九章 PHP中的数组与数据结构

9.1 数组的分类

9.2 数组的定义

$数组变量名[下标]=资料内容    //其中索引值（下标）可以是一个字符串或一个整数

<?php
$contact1[0]=1;
$contact1[1]="高某";
$contact1[2]="A公司";
$contact1[3]="（010）98765432";
$contact1[4]="gao@brophp.com";
?>

<?php
$contact1["Id"]=1;
$contact1["Name"]="高某";
$contact1["Company"]="A公司";
$contact1["Tel"]="（010）98765432";
$contact1["Email"]="gao@brophp.com";
?>

<?php
$contact1["Id"]=1;
$contact1[0]=1;
$contact1["Name"]="高某";
$contact1[1]="高某";
$contact1["Company"]="A公司";
$contact1[2]="A公司";
?>

<?php
$contact1[]=1;
$contact1[]="高某";
$contact1[]="A公司";
$contact1[]="（010）98765432";
$contact1[]="gao@brophp.com";
?>

<?php
$contact1[]=1;
$contact1[14]="高某";
$contact1[]="A公司";
$contact1[14]="（010）98765432";
$contact1[]="gao@brophp.com";
?>

print_r()

var_dump()

array (size=4)
0 => int 1
14 => string '（010）98765432' (length=15)
15 => string 'A公司' (length=5)
16 => string 'gao@brophp.com' (length=14)

print_r()

var_dump

var_dump — 打印变量的相关信息

void var_dump ( mixed $expression [, mixed $... ] )

<?php
$a = array(1, 2, array("a", "b", "c"));
var_dump($a);
?>

array(3) {
[0]=>
int(1)
[1]=>
int(2)
[2]=>
array(3) {
[0]=>
string(1) "a"
[1]=>
string(1) "b"
[2]=>
string(1) "c"
}
}

<?php

$b = 3.1;
$c = true;
var_dump($b, $c);

?>

float(3.1)
bool(true)

print_r — 打印关于变量的易于理解的信息。

bool print_r ( mixed $expression [, bool $return ] )

print_r()

string

integer

float

array

object

print_r()

reset()

<pre>
<?php
$a = array ('a' => 'apple', 'b' => 'banana', 'c' => array ('x','y','z'));
print_r ($a);
?>
</pre>

<pre>
Array
(
[a] => apple
 => banana
[c] => Array
(
[0] => x
[1] => y
[2] => z
)
)
</pre>

print_r()

return

print_r()

<?php
$b = array ('m' => 'monkey', 'foo' => 'bar', 'x' => array ('x', 'y', 'z'));
$results = print_r ($b, true); //$results 包含了 print_r 的输出结果
?>

$数组变量名=array(key1=>value1,key2=>value2,……keyN=>valueN);

$contact1=array(1,14=>"高某","A公司","北京市",14=>"(010)98765432","gao@brophp.com");

Array ( [0] => 1 [14] => (010)98765432 [15] => A公司 [16] => 北京市 [17] => gao@brophp.com )

<?php
$contact1=array(
array(1,'高某','A公司','北京市','(010)98765432','gm@linux.com'),
array(2,'洛某','B公司','上海市','(021)12345678','lm@apache.com'),
array(3,'峰某','C公司','天津市','(022)2468246','fm@mysql.com'),
);
?>

Array (
[0] => Array (
[0] => 1
[1] => 高某
[2] => A公司
[3] => 北京市
[4] => (010)98765432
[5] => gm@linux.com )
[1] => Array (
[0] => 2
[1] => 洛某
[2] => B公司
[3] => 上海市
[4] => (021)12345678
[5] => lm@apache.com )
[2] => Array (
[0] => 3
[1] => 峰某
[2] => C公司
[3] => 天津市
[4] => (022)2468246
[5] => fm@mysql.com )
)

<?php
$contact1=array(
"北京联系人"=>array(1,'高某','A公司','北京市    ','(010)98765432','gm@linux.com'),
"上海联系人"=>array(2,'洛某','B公司','上海市','(021)12345678','lm@apache.com'),
"天津联系人"=>array(3,'风某','C公司','天津市','(022)2468246','fm@mysql.com'),
);
?>

<?php
echo "第一个联系人的公司：".$contact1[0][2]."<br />";
echo "上海联系人的E-mail：".$contact1["上海联系人"][2]."<br />";
>

<?php
$contact=array(1,'高某','A公司','北京市','(010)98765432','gao@brophp.com');

echo '<table border="1" width="600" align="center">';
echo '<caption><h1>联系人列表</h1></caption>';
echo '<tr bgcolor="#DDDDDD">';
echo '<th>编号</th><th>姓名</th><th>公司</th><th>地址</th><th>电话</th><th>E-mail</th>';
echo '</tr><tr>';
for($i=0;$i<count($contact);$i++)
echo '<td>'.$contact[$i].'</td>';
echo '</tr></table>';
?>

foreach (array_expression as $value)
statement

foreach (array_expression as $key => $value)
statement

array_expression

$value

$key

foreach

foreach

reset()

foreach

$value

&

<?php
$arr = array(1, 2, 3, 4);
foreach ($arr as &$value) {
$value = $value * 2;
}
// $arr is now array(2, 4, 6, 8)
unset($value); // 最后取消掉引用
?>

$value

<?php
foreach (array(1, 2, 3, 4) as &$value) {
$value = $value * 2;
}
?>

<?php
$arr = array("one", "two", "three");
reset($arr);
while (list(, $value) = each($arr)) {
echo "Value: $value<br>\n";
}

foreach ($arr as $value) {
echo "Value: $value<br />\n";
}
?>

<?php
$arr = array("one", "two", "three");
reset($arr);
while (list($key, $value) = each($arr)) {
echo "Key: $key; Value: $value<br />\n";
}

foreach ($arr as $key => $value) {
echo "Key: $key; Value: $value<br />\n";
}
?>

9.3.3 联合使用list()、each()和while循环遍历数组

1.each()函数

array each ( array &$array )

<?php
$foo = array("bob", "fred", "jussi", "jouni", "egon", "marliese");
$bar = each($foo);
print_r($bar);
?>

$bar

Array
(
[1] => bob
[value] => bob
[0] => 0
[key] => 0
)

<?php
$foo = array("Robert" => "Bob", "Seppo" => "Sepi");
$bar = each($foo);
print_r($bar);
?>

$bar

Array
(
[1] => Bob
[value] => Bob
[0] => Robert
[key] => Robert
)

<?php
$fruit = array('a' => 'apple', 'b' => 'banana', 'c' => 'cranberry');

reset($fruit);
while (list($key, $val) = each($fruit)) {
echo "$key => $val\n";
}
?>

a => apple
b => banana
c => cranberry

$fruit

2.list()函数

list()

<?php
$array = [
[1, 2],
[3, 4],
];

foreach ($array as list($a, $b)) {
// $a contains the first element of the nested array,
// and $b contains the second element.
echo "A: $a; B: $b\n";
}
?>

A: 1; B: 2
A: 3; B: 4

list()

<?php
$array = [
[1, 2],
[3, 4],
];

foreach ($array as list($a)) {
// Note that there is no $b here.
echo "$a\n";
}
?>

1
3

while (expr)
statement

while (expr):
statement
...
endwhile;

<?php
/* example 1 */

$i = 1;
while ($i <= 10) {
echo $i++;  /* the printed value would be $i before the increment(post-increment) */
}

/* example 2 */

$i = 1;
while ($i <= 10):
print $i;
$i++;
endwhile;
?>

while(list($key,$value)=each(array_expression))
{
循环体；
}

9.3.4 使用数组的内部指针控制函数遍历数组

9.2 预定义数组

$_SERVER:变量由Web服务器设定或者直接与当前脚本的执行环境相关联
$_ENV:执行环境提交至脚本的变量
$_GET:经由URL请求提交至脚本的变量
$_POST:经由HTTP POST方法提交至脚本的变量
$_REQUEST:经由GET，POST和COOKIE机制提交至脚本的变量，因此该函数并不值得信任
$_FILES:经由HTTP POST文件上传而提交至脚本的变量
$_COOKIE:经由HTTP Cookies方法提交至脚本的变量
$_SESSION:当前注册给脚本会话的变量
$GLOBALS:包含一个引用指向每个当前脚本的全局范围内有效的变量。该数组的键名为全局变量的名称

9.4.1 服务器变量：$_SERVER

$_SERVER

$HTTP_SERVER_VARS[已弃用]

$_SERVER

$HTTP_SERVER_VARS

$HTTP_SERVER_VARS

$_SERVER

$_SERVER

$_SERVER

<?php
foreach($_SERVER as $key=>$value){
echo '$_SERVER['.$key.'] = ' .$value.'<br>';
}
echo '<pre>';
print_r($_SERVER);
echo '</pre>';
echo $_SERVER['REMOTE_ADDR'];
?>

9.4.2 环境变量：$_ENV

$_ENV

$HTTP_ENV_VARS [已弃用]

$HTTP_ENV_VARS

$HTTP_ENV_VARS

$_ENV

$_ENV

<?php
foreach($_ENV as $key=>$value){
echo '$_ENV['.$key.'] = '.$value.'<br />'
}
?>

9.4.3 URL GET变量：$_GET

$_GET

$_GET

http://www.brophp.com/index.php?action=1&user=lamp&tid=10&page=5

<?php
echo '参数为action为：'.$_GET["action"].'<br>';
echo '参数为user为：'.$_GET["user"].'<br>';
echo '参数为tid为：'.$_GET["tid"].'<br>';
echo '参数为page为：'.$_GET["page"].'<br>';

echo '<pre>';
print_r($_GET);
echo '</pre>';
?>

$_GET

9.4.4 HTTP POST变量：$_POST

$_POST

$_POST

$_GET

$_POST

<html>
<head><title>添加联系人</head></title>
<body>
<form action="add.php" method="post">
编号：<input type="text" name="id"><br>
姓名：<input type="text" name="name"><br>
公司：<input type="text" name="company"><br>
地址：<input type="text" name="address"><br>
电话：<input type="text" name="phone"><br>
Email<input type="text" name="email"><br>
<input type="submit" value="添加联系人">
</form>
</body>
</html>

$_POST

$_POST["address"]

<?php
echo "用户添加的联系人信息如下：".'<br>';
foreach($_POST as $key=>$value)
echo $key.':'.$value.'<br>';
?>

9.4.5 request变量：$_REQUEST

$_GET

$_POST

$_COOKIE

$_POST["address"]

$_REQUEST

9.4.6 HTTP文件上传变量：$_FILES

$_POST

$_FILES

9.4.7 HTTP Cookies:$_COOKIE

$_COOKIE

$_COOKIE

9.4.8 Session变量：$_SESSION

9.4.9 Global变量：$GLOBALS

$GLOBALS

<?php
$a=1;
$b=2;
function Sum{
$GLOBALS['b']=$GLOBALS['a']+$BLOGALS['b'];
}

Sum();
echo $b;
?>

9.5 数组的相关处理函数

9.5.1 数组的键/值操作函数

1. 函数array_values()

array array_values ( array $input )

input

<?php
$array = array("size" => "XL", "color" => "gold");
print_r(array_values($array));
?>

Array
(
[0] => XL
[1] => gold
)

2. 函数array_keys()

array array_keys ( array $array [, mixed $search_value [, bool $strict = false ]] )

array_keys()

input

search_value

input

input

search_value

strict

<?php
$array = array(0 => 100, "color" => "red");
print_r(array_keys($array));

$array = array("blue", "red", "green", "blue", "blue");
print_r(array_keys($array, "blue"));

$array = array("color" => array("blue", "red", "green"),
"size"  => array("small", "medium", "large"));
print_r(array_keys($array));
?>

Array
(
[0] => 0
[1] => color
)
Array
(
[0] => 0
[1] => 3
[2] => 4
)
Array
(
[0] => color
[1] => size
)

3. 函数in_array()

bool in_array ( mixed $needle , array $haystack [, bool $strict = FALSE ] )

needle

haystack

strict

<?php
$os = array("Mac", "NT", "Irix", "Linux");
if (in_array("Irix", $os)) {
echo "Got Irix";
}
if (in_array("mac", $os)) {
echo "Got mac";
}
?>

Got Irix

<?php
$a = array('1.10', 12.4, 1.13);

if (in_array('12.4', $a, true)) {
echo "'12.4' found with strict check\n";
}

if (in_array(1.13, $a, true)) {
echo "1.13 found with strict check\n";
}
?>

1.13 found with strict check

<?php
$a = array(array('p', 'h'), array('p', 'r'), 'o');

if (in_array(array('p', 'h'), $a)) {
echo "'ph' was found\n";
}

if (in_array(array('f', 'i'), $a)) {
echo "'fi' was found\n";
}

if (in_array('o', $a)) {
echo "'o' was found\n";
}
?>

'ph' was found
'o' was found

4. 函数array_flip()

array array_flip ( array $trans )

array_flip()

trans

trans

integer

string

<?php
$trans = array("a" => 1, "b" => 1, "c" => 2);
$trans = array_flip($trans);
print_r($trans);
?>

Array
(
[1] => b
[2] => c
)

5. 函数array_reverse()

array array_reverse ( array $array [, bool $preserve_keys = false ] )

array

preserve_keys

<?php
$input  = array("php", 4.0, array("green", "red"));
$result = array_reverse($input);
$result_keyed = array_reverse($input, true);
?>

$result

$result_keyed

$result

$result_keyed

Array
(
[0] => Array
(
[0] => green
[1] => red
)

[1] => 4
[2] => php
)
Array
(
[2] => Array
(
[0] => green
[1] => red
)

[1] => 4
[0] => php
)

9.5.2 统计数组元素的个数和唯一性

1. 函数count()

int count ( mixed $var [, int $mode = COUNT_NORMAL ] )

Countable

count()

Countable::count()

count()

var

mode

<?php
$a[0] = 1;
$a[1] = 3;
$a[2] = 5;
$result = count($a);
// $result == 3

$b[0]  = 7;
$b[5]  = 9;
$b[10] = 11;
$result = count($b);
// $result == 3

$result = count(null);
// $result == 0

$result = count(false);
// $result == 1
?>

<?php
$food = array('fruits' => array('orange', 'banana', 'apple'),
'veggie' => array('carrot', 'collard', 'pea'));

// recursive count
echo count($food, COUNT_RECURSIVE); // output 8

// normal count
echo count($food); // output 2

?>

2. 函数array_count_value()

array array_count_values ( array $input )

<?php
$array = array(1, "hello", 1, "world", "hello");
print_r(array_count_values($array));
?>

Array
(
[1] => 2
[hello] => 2
[world] => 1
)

3. 函数array_unique()

array array_unique ( array $array [, int $sort_flags = SORT_STRING ] )

array_unique()

array_unique()

(string) $elem1 === (string) $elem2

<?php
$input = array("a" => "green", "red", "b" => "green", "blue", "red");
$result = array_unique($input);
print_r($result);
?>

Array
(
[a] => green
[0] => red
[1] => blue
)

<?php
$input = array(4, "4", "3", 4, 3, "3");
$result = array_unique($input);
var_dump($result);
?>

array(2) {
[0] => int(4)
[2] => string(1) "3"
}

9.5.3 使用回调函数处理数组的函数

1. 函数array_filter()

array array_filter ( array $input [, callable $callback = "" ] )

<?php
function odd($var)
{
// returns whether the input integer is odd
return($var & 1);
}

function even($var)
{
// returns whether the input integer is even
return(!($var & 1));
}

$array1 = array("a"=>1, "b"=>2, "c"=>3, "d"=>4, "e"=>5);
$array2 = array(6, 7, 8, 9, 10, 11, 12);

echo "Odd :\n";
print_r(array_filter($array1, "odd"));
echo "Even:\n";
print_r(array_filter($array2, "even"));
?>

Odd :
Array
(
[a] => 1
[c] => 3
[e] => 5
)
Even:
Array
(
[0] => 6
[2] => 8
[4] => 10
[6] => 12
)

<?php

$entry = array(
0 => 'foo',
1 => false,
2 => -1,
3 => null,
4 => ''
);

print_r(array_filter($entry));
?>

Array
(
[0] => foo
[2] => -1
)

2. 函数array_walk()

bool array_walk ( array &$array , callable $funcname [, mixed $userdata = NULL ] )

funcname

array

array_walk()

array_walk()

array_walk()

funcname

E_WARNING

array_walk()

error_reporting()

<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");

function test_alter(&$item1, $key, $prefix)
{
$item1 = "$prefix: $item1";
}

function test_print($item2, $key)
{
echo "$key. $item2<br />\n";
}

echo "Before ...:\n";
array_walk($fruits, 'test_print');

array_walk($fruits, 'test_alter', 'fruit');
echo "... and after:\n";

array_walk($fruits, 'test_print');
?>

Before ...:
d. lemon
a. orange
b. banana
c. apple
... and after:
d. fruit: lemon
a. fruit: orange
b. fruit: banana
c. fruit: apple

3. 函数array_map()

array array_map ( callable $callback , array $arr1 [, array $... ] )

array_map()

arr1

callback

array_map()

<?php
function myfun1($v){
if($v==="MySQL"){
return "Oracle";
}
return $v;
}

$lamp=array("Linux","Apache","MySQL","PHP");
print_r(array_map("myfun1",$lamp));

function myfun2($v1,$v2){
if($v1===$v2){
return "same";
}
return "different";
}

$a1=array("Linux","PHP","MySQL");
$a2=array("Unix","PHP","Oracle");
print_r(array_map("myfun2",$a1,$a2));

$a1=array("Linux","Apache");
$a2=array("MySQL","PHP");
print_r(array_map(null, $a1,$a2));
?>

9.5.4 数组的排序函数

1. 简单的数组排序函数 sort()和rsort()

bool sort ( array &$array [, int $sort_flags = SORT_REGULAR ] )

<?php

$fruits = array("lemon", "orange", "banana", "apple");
sort($fruits);
foreach ($fruits as $key => $val) {
echo "fruits[" . $key . "] = " . $val . "\n";
}

?>

fruits[0] = apple
fruits[1] = banana
fruits[2] = lemon
fruits[3] = orange

<?php

$fruits = array(
"Orange1", "orange2", "Orange3", "orange20"
);
sort($fruits, SORT_NATURAL | SORT_FLAG_CASE);
foreach ($fruits as $key => $val) {
echo "fruits[" . $key . "] = " . $val . "\n";
}

?>

fruits[0] = Orange1
fruits[1] = orange2
fruits[2] = Orange3
fruits[3] = orange20

bool rsort ( array &$array [, int $sort_flags = SORT_REGULAR ] )

<?php
$fruits = array("lemon", "orange", "banana", "apple");
rsort($fruits);
foreach ($fruits as $key => $val) {
echo "$key = $val\n";
}
?>

0 = orange
1 = lemon
2 = banana
3 = apple

2. 根据键名对数组排序 ksort()和krsort()

bool ksort ( array &$array [, int $sort_flags = SORT_REGULAR ] )

<?php
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");
ksort($fruits);
foreach ($fruits as $key => $val) {
echo "$key = $val\n";
}
?>

a = orange
b = banana
c = apple
d = lemon

bool krsort ( array &$array [, int $sort_flags = SORT_REGULAR ] )

<?php
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");
krsort($fruits);
foreach ($fruits as $key => $val) {
echo "$key = $val\n";
}
?>

d = lemon
c = apple
b = banana
a = orange

3. 根据元素的值对数组排序 asort()和arsort()

bool asort ( array &$array [, int $sort_flags = SORT_REGULAR ] )

<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
asort($fruits);
foreach ($fruits as $key => $val) {
echo "$key = $val\n";
}
?>

c = apple
b = banana
d = lemon
a = orange

bool arsort ( array &$array [, int $sort_flags = SORT_REGULAR ] )

<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
arsort($fruits);
foreach ($fruits as $key => $val) {
echo "$key = $val\n";
}
?>

a = orange
d = lemon
b = banana
c = apple

4. 根据“自然排序”法对数组排序 natcasesort()

bool natcasesort ( array &$array )

<?php
$array1 = $array2 = array('IMG0.png', 'img12.png', 'img10.png', 'img2.png', 'img1.png', 'IMG3.png');

sort($array1);
echo "Standard sorting\n";
print_r($array1);

natcasesort($array2);
echo "\nNatural order sorting (case-insensitive)\n";
print_r($array2);
?>

Standard sorting
Array
(
[0] => IMG0.png
[1] => IMG3.png
[2] => img1.png
[3] => img10.png
[4] => img12.png
[5] => img2.png
)

Natural order sorting (case-insensitive)
Array
(
[0] => IMG0.png
[4] => img1.png
[3] => img2.png
[5] => IMG3.png
[2] => img10.png
[1] => img12.png
)

5. 根据用户自定的规则对数组排序 usort()、uasort()和uksort()

bool usort ( array &$array , callable $cmp_function )

<?php
function cmp($a, $b)
{
if ($a == $b) {
return 0;
}
return ($a < $b) ? -1 : 1;
}

$a = array(3, 2, 5, 6, 1);

usort($a, "cmp");

foreach ($a as $key => $value) {
echo "$key: $value\n";
}
?>

0: 1
1: 2
2: 3
3: 5
4: 6

<?php
function cmp($a, $b)
{
return strcmp($a["fruit"], $b["fruit"]);
}

$fruits[0]["fruit"] = "lemons";
$fruits[1]["fruit"] = "apples";
$fruits[2]["fruit"] = "grapes";

usort($fruits, "cmp");

while (list($key, $value) = each($fruits)) {
echo "$fruits[$key]: " . $value["fruit"] . "\n";
}
?>

$fruits[0]: apples
$fruits[1]: grapes
$fruits[2]: lemons

bool uasort ( array &$array , callable $cmp_function )

<?php
// Comparison function
function cmp($a, $b) {
if ($a == $b) {
return 0;
}
return ($a < $b) ? -1 : 1;
}

// Array to be sorted
$array = array('a' => 4, 'b' => 8, 'c' => -1, 'd' => -9, 'e' => 2, 'f' => 5, 'g' => 3, 'h' => -4);
print_r($array);

// Sort and print the resulting array
uasort($array, 'cmp');
print_r($array);
?>

Array
(
[a] => 4
 => 8
[c] => -1
[d] => -9
[e] => 2
[f] => 5
[g] => 3
[h] => -4
)
Array
(
[d] => -9
[h] => -4
[c] => -1
[e] => 2
[g] => 3
[a] => 4
[f] => 5
[b] => 8
)

bool uksort ( array &$array , callable $cmp_function )

<?php
function cmp($a, $b)
{
$a = preg_replace('@^(a|an|the) @', '', $a);
$b = preg_replace('@^(a|an|the) @', '', $b);
return strcasecmp($a, $b);
}

$a = array("John" => 1, "the Earth" => 2, "an apple" => 3, "a banana" => 4);

uksort($a, "cmp");

foreach ($a as $key => $value) {
echo "$key: $value\n";
}
?>

an apple: 3
a banana: 4
the Earth: 2
John: 1

array array_slice ( array $array , int $offset [, int $length = NULL [, bool $preserve_keys = false ]] )

array

offset

length

preserve_keys

<?php
$input = array("a", "b", "c", "d", "e");

$output = array_slice($input, 2);      // returns "c", "d", and "e"
$output = array_slice($input, -2, 1);  // returns "d"
$output = array_slice($input, 0, 3);   // returns "a", "b", and "c"

// note the differences in the array keys
print_r(array_slice($input, 2, -1));
print_r(array_slice($input, 2, -1, true));
?>

Array
(
[0] => c
[1] => d
)
Array
(
[2] => c
[3] => d
)

2. 函数array_splice()

array array_splice ( array &$input , int $offset [, int $length = 0 [, mixed $replacement ]] )

input

offset

length

replacement

<?php
$input = array("red", "green", "blue", "yellow");
array_splice($input, 2);
// $input is now array("red", "green")

$input = array("red", "green", "blue", "yellow");
array_splice($input, 1, -1);
// $input is now array("red", "yellow")

$input = array("red", "green", "blue", "yellow");
array_splice($input, 1, count($input), "orange");
// $input is now array("red", "orange")

$input = array("red", "green", "blue", "yellow");
array_splice($input, -1, 1, array("black", "maroon"));
// $input is now array("red", "green",
//          "blue", "black", "maroon")

$input = array("red", "green", "blue", "yellow");
array_splice($input, 3, 0, "purple");
// $input is now array("red", "green",
//          "blue", "purple", "yellow");
?>

<?php
array_push($input, $x, $y);
array_splice($input, count($input), 0, array($x, $y));
array_pop($input);
array_splice($input, -1);
array_shift($input);
array_splice($input, 0, 1);
array_unshift($input, $x, $y);
array_splice($input, 0, 0, array($x, $y));
$input[$x] = $y; // 对于键名和偏移量等值的数组
array_splice($input, $x, 1, $y);
?>

3. 函数array_combine()

array array_combine ( array $keys , array $values )

keys

values

<?php
$a = array('green', 'red', 'yellow');
$b = array('avocado', 'apple', 'banana');
$c = array_combine($a, $b);

print_r($c);
?>

Array
(
[green]  => avocado
[red]    => apple
[yellow] => banana
)

4. 函数array_merge()

array array_merge ( array $array1 [, array $... ] )

<?php
$array1 = array("color" => "red", 2, 4);
$array2 = array("a", "b", "color" => "green", "shape" => "trapezoid", 4);
$result = array_merge($array1, $array2);
print_r($result);
?>

Array
(
[color] => green
[0] => 2
[1] => 4
[2] => a
[3] => b
[shape] => trapezoid
[4] => 4
)

<?php
$array1 = array();
$array2 = array(1 => "data");
$result = array_merge($array1, $array2);
?>

Array
(
[0] => data
)

<?php
$array1 = array(0 => 'zero_a', 2 => 'two_a', 3 => 'three_a');
$array2 = array(1 => 'one_b', 3 => 'three_b', 4 => 'four_b');
$result = $array1 + $array2;
var_dump($result);
?>

array(5) {
[0]=>
string(6) "zero_a"
[2]=>
string(5) "two_a"
[3]=>
string(7) "three_a"
[1]=>
string(5) "one_b"
[4]=>
string(6) "four_b"
}

5. 函数array_interset()

array array_intersect ( array $array1 , array $array2 [, array $ ... ] )

<?php
$array1 = array("a" => "green", "red", "blue");
$array2 = array("b" => "green", "yellow", "red");
$result = array_intersect($array1, $array2);
print_r($result);
?>

Array
(
[a] => green
[0] => red
)

(string) $elem1 === (string) $elem2

6. 函数array_diff()

array array_diff ( array $array1 , array $array2 [, array $... ] )

<?php
$array1 = array("a" => "green", "red", "blue", "red");
$array2 = array("b" => "green", "yellow", "red");
$result = array_diff($array1, $array2);

print_r($result);
?>

Array
(
[1] => blue
)

(string) $elem1 === (string) $elem2

array_diff($array1[0], $array2[0]);

9.5.6 数组与数据结构

1. 使用数组实现堆栈

array_push()

array_pop()

int array_push ( array &$array , mixed $var [, mixed $... ] )

<?php
$array[] = $var;
?>

$array[] =

$var[]

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

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

mixed array_pop ( array &$array )

<?php
$stack = array("orange", "banana", "apple", "raspberry");
$fruit = array_pop($stack);
print_r($stack);
?>

$stack

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

$fruit

2. 使用数组实现队列

mixed array_shift ( array &$array )

<?php
$stack = array("orange", "banana", "apple", "raspberry");
$fruit = array_shift($stack);
print_r($stack);
?>

Array
(
[0] => banana
[1] => apple
[2] => raspberry
)

9.5.7 其他有用的数组处理函数

1. 函数array_rand()

mixed array_rand ( array $input [, int $num_req = 1 ] )

<?php
$input = array("Neo", "Morpheus", "Trinity", "Cypher", "Tank");
$rand_keys = array_rand($input, 2);
echo $input[$rand_keys[0]] . "\n";
echo $input[$rand_keys[1]] . "\n";
?>

2. 函数shuffle()

bool shuffle ( array &$array )

<?php
$numbers = range(1, 20);
shuffle($numbers);
foreach ($numbers as $number) {
echo "$number ";
}
?>

3.函数array_sum()

number array_sum ( array $array )

<?php
$a = array(2, 4, 6, 8);
echo "sum(a) = " . array_sum($a) . "\n";

$b = array("a" => 1.2, "b" => 2.3, "c" => 3.4);
echo "sum(b) = " . array_sum($b) . "\n";
?>

sum(a) = 20
sum(b) = 6.9

4. 函数range()

array range ( mixed $start , mixed $limit [, number $step = 1 ] )

start

limit

step

<?php
// array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
foreach (range(0, 12) as $number) {
echo $number;
}

// The step parameter was introduced in 5.0.0
// array(0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100)
foreach (range(0, 100, 10) as $number) {
echo $number;
}

// Use of character sequences introduced in 4.1.0
// array('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i');
foreach (range('a', 'i') as $letter) {
echo $letter;
}
// array('c', 'b', 'a');
foreach (range('c', 'a') as $letter) {
echo $letter;
}
?>

9.6 操作PHP数组需要注意的一些细节

9.6.1 数组运算符号

<? php
$a=array("a"=>"Linux","b"=>"Apache");
$b=array("a"=>"PHP","b"=>"MySQL","c"=>"web");

$c=$a+$b;
echo "合并后的 \$a和\$b:\n";
print_r($c);

$c=$b+$a;
echo "合并后的 \$a和\$b:\n";
print_r($c);
?>

合并后的 $a和$b:
Array (
[a] => Linux
 => Apache
[c] => web
)
合并后的 $a和$b:
Array (
[a] => PHP
[b] => MySQL
[c] => web
)

void unset ( mixed $var [, mixed $... ] )

<?php
function destroy_foo() {
global $foo;
unset($foo);
}

$foo = 'bar';
destroy_foo();
echo $foo;
?>

bar

$GLOBALS

<?php
function foo()
{
unset($GLOBALS['bar']);
}

$bar = "something";
foo();
?>

<?php
function foo(&$bar) {
unset($bar);
$bar = "blah";
}

$bar = 'something';
echo "$bar\n";

foo($bar);
echo "$bar\n";
?>

Before unset: 1, after unset: 23
Before unset: 2, after unset: 23
Before unset: 3, after unset: 23

9.6.3 关于数组下标的注意事项

$foo['bar']

$foo[bar]

$foo[bar]

<?php
$array=array(1,2,3,4,5,6,7,8,9);
for($i=0;$i<count($array);$i++){
echo "<br>查看 $i:<br>";
echo "坏的：".$array['$i']."<br>";
echo "好的：".$array[$i]."<br>";
echo "坏的：{$array['$i']}<br>";
echo "好的：{$array[$i]}<br>";
}
?>