对于Web编程来说，最重要的就是存取和读写数据了。存储方式可能有很多种，可以是字符串、数组、文件的形式等。数组，可以说是PHP的数据应用中较重要的一种方式。PHP的数组函数众多，下面是我学习的小结，借此记之，便于以后鉴之。
1. 数组定义
数组的定义使用 array()方式定义，可以定义空数组：
01 |
<?php |
02 |
$number = array(1,3,5,7,9); |
03 |
//定义空数组 |
04 |
$result = array(); |
05 |
$color =array("red","blue","green"); |
06 |
//自定义键值 |
07 |
$language = (1=>"English",3=>"Chinese",5=>"Franch"); |
08 |
//定义二维数组 |
09 |
$two = array( |
10 |
"color"=>array("red","blue"), //用逗号结尾 |
11 |
"week"=>array("Monday","Friday") //最后一句没有标点 |
12 |
)； |
13 |
?> |
2. 创建数组
compact()
compact()函数——将一个或多个变量（包含数组）转换为数组：array compact ( mixed $varname [, mixed $... ] )。
1 |
<?PHP |
2 |
$number = "1,3,5,7,9"; |
3 |
$string = "I'm PHPer"; |
4 |
$array = array("And","You?"); |
5 |
$newArray = compact("number","string","array"); |
6 |
print_r ($newArray); |
7 |
?> |
compact()函数用于将两个或多个变量转换为数组，当然也包含数组变量。其参数是变量的名称而非带有$全名。相反的函数是extract()作用顾名思义就是将数组转换为单个的字符串，键值作为其字符串名称，数组值作为字符串的值。
运行结果:
1 |
Array ( |
2 |
[number] => 1,3,5,7,9 |
3 |
[string] => I'm PHPer |
4 |
[array] => Array ( [0] => And [1] => You? ) |
5 |
) |
array_combine()
array_combine()——将两个数组重组成一个数组,一个作键值一个做的值：array array_combine ( array $keys , array $values )
1 |
<?PHP |
2 |
$number = array("1","3","5","7","9"); |
3 |
$array = array("I","Am","A","PHP","er"); |
4 |
$newArray = array_combine($number,$array); |
5 |
print_r ($newArray); |
6 |
?> |
array_combine函数不多说了，谁看了都明白。
运行结果：
1 |
Array ( [1] => I [3] => Am [5] => A [7] => PHP [9] => er ) |
range()
range()函数——创建指定范围的数组：
01 |
<?PHP |
02 |
$array1 = range(0,100,10);//0为起始值，100为结束值，10为步进值(默认步进值为1). |
03 |
print_r($array1); |
04 |
echo"<br />"; |
05 |
$array2 = range("A","Z"); |
06 |
print_r($array2); |
07 |
echo "<br />"; |
08 |
$array3 = range("z","a"); |
09 |
print_r($array3); |
10 |
?> |
array_fill()
array_fill()函数——填充数组函数：
01 |
<?PHP |
02 |
$array = range(1,10); |
03 |
$fillarray = range("a","d"); |
04 |
$arrayFilled = array_fill(0,5,$fillarray);//这里的$fillarray可以是字符串，如"test". |
05 |
echo "<pre>"; |
06 |
print_r ($arrayFilled); |
07 |
echo "</pre>"; |
08 |
$keys = array("string","2",9,"SDK","PK"); |
09 |
$array2 = array_fill_keys($keys,"testing"); |
10 |
echo "<pre>"; |
11 |
print_r ($array2); |
12 |
echo "</pre>"; |
13 |
?> |
运行结果：
01 |
Array |
02 |
( |
03 |
[0] => Array |
04 |
( |
05 |
[0] => a |
06 |
[1] => b |
07 |
[2] => c |
08 |
[3] => d |
09 |
) |
10 |
11 |
[1] => Array |
12 |
( |
13 |
[0] => a |
14 |
[1] => b |
15 |
[2] => c |
16 |
[3] => d |
17 |
) |
18 |
19 |
[2] => Array |
20 |
( |
21 |
[0] => a |
22 |
[1] => b |
23 |
[2] => c |
24 |
[3] => d |
25 |
) |
26 |
27 |
[3] => Array |
28 |
( |
29 |
[0] => a |
30 |
[1] => b |
31 |
[2] => c |
32 |
[3] => d |
33 |
) |
34 |
35 |
[4] => Array |
36 |
( |
37 |
[0] => a |
38 |
[1] => b |
39 |
[2] => c |
40 |
[3] => d |
41 |
) |
42 |
43 |
) |
44 |
Array |
45 |
( |
46 |
[string] => testing |
47 |
[2] => testing |
48 |
[9] => testing |
49 |
[SDK] => testing |
50 |
[PK] => testing |
51 |
) |
3. 数组的遍历
foreach遍历
foreach (array_expression as $value){}
foreach (array_expression as $key => $value){}
1 |
<?PHP |
2 |
$speed = array(50,120,180,240,380); |
3 |
foreach($speed as $keys=>$values){ |
4 |
echo $keys."=>".$values."<br />"; |
5 |
} |
6 |
?> |
运行结果：
1 |
0=>50 |
2 |
1=>120 |
3 |
2=>180 |
4 |
3=>240 |
5 |
4=>380 |
while循环遍历
while循环遍历一般结合list函数，以下是实例
01 |
<?PHP |
02 |
$staff = array( |
03 |
array("姓名","性别","年龄"), |
04 |
array("小张","男",24), |
05 |
array("小王","女",25), |
06 |
array("小李","男",23) |
07 |
); |
08 |
echo "<table border=2>"; |
09 |
while(list($keys,$value) = each($staff)){ |
10 |
list($name,$sex,$age) = $value; |
11 |
echo "<tr><td>$name</td><td>$sex</td><td>$age</td></tr>"; |
12 |
} |
13 |
echo "</table>"; |
14 |
?> |
for循环遍历
1 |
<?PHP |
2 |
$speed = range(0,220,20); |
3 |
for($i =0;$i<count($speed);$i++) { |
4 |
echo $speed[$i]." "; |
5 |
} |
6 |
?> |
运行结果：
1 |
0 20 40 60 80 100 120 140 160 180 200 220 |
4. 数组的指针操作
涉及函数包括reset、prev、end、next、current、each。
实例一：next 与 prev
01 |
<?PHP |
02 |
$speed = range(0,220,20); |
03 |
echo current($speed);//输出当前位置的值（在数组的开头位置） |
04 |
$i = rand(1,11); |
05 |
while($i--){ |
06 |
next($speed);//指针从当前位置向后移动一位 |
07 |
} |
08 |
echo current($speed);//输出当前位置的值 |
09 |
echo "<br />"; |
10 |
echo prev($speed);//输出前一位置数组值 |
11 |
echo "<br />"; |
12 |
echo reset($speed);//重置数组的指针，将指针指向起始位置 |
13 |
echo "<br />"; |
14 |
echo end($speed);//输出最后位置的数组值 |
15 |
echo "<br />"; |
16 |
?> |
运行结果：
1 |
0220 |
2 |
200 |
3 |
0 |
4 |
220 |
实例二：each函数指针操作
01 |
<?PHP |
02 |
$speed = range(0,200,40); |
03 |
echo "each实现指针下移 <br />"; |
04 |
echo "0挡的速度是".current(each($speed))."<br />"; |
05 |
echo "1挡的速度是".current(each($speed))."<br />"; |
06 |
echo "2挡的速度是".current(each($speed))."<br />"; |
07 |
echo "3挡的速度是".current(each($speed))."<br />"; |
08 |
echo "4挡的速度是".current(each($speed))."<br />"; |
09 |
echo "5挡的速度是".current(each($speed))."<br />"; |
10 |
echo "使用each函数实现数组指针的移动，进行数组遍历 <br />"; |
11 |
reset($speed);//这里是将数组指针指向数组首 |
12 |
while(list($key,$value)=each($speed)){ |
13 |
echo $key."=>".$value."<br />"; |
14 |
} |
15 |
?> |
运行结果：
01 |
each实现指针下移 |
02 |
0挡的速度是0 |
03 |
1挡的速度是40 |
04 |
2挡的速度是80 |
05 |
3挡的速度是120 |
06 |
4挡的速度是160 |
07 |
5挡的速度是200 |
08 |
使用each函数实现数组指针的移动，进行数组遍历 |
09 |
0=>0 |
10 |
1=>40 |
11 |
2=>80 |
12 |
3=>120 |
13 |
4=>160 |
14 |
5=>200 |
5. 数组的增添删改操作
增添数组成员
实例一：$num[] = value直接赋值追加到数组末尾：
1 |
<?PHP |
2 |
$num = array(1=>80,2=>120,3=>160); |
3 |
echo "使用表达式添加数组成员<br />"; |
4 |
$num[]=240; |
5 |
print_r($num); |
6 |
?> |
运行结果：
1 |
使用表达式添加数组成员 |
2 |
Array ( [0] => 80 [1] => 120 [2] => 160 [3] => 240 ) |
实例二：array_pad函数，数组数组首尾选择性追加
1 |
<?PHP |
2 |
$num = array(1=>80,2=>120,3=>160); |
3 |
$num = array_pad($num,4,200); |
4 |
echo "使用array_pad函数向数组尾部添加成员<br />"; |
5 |
print_r($num); |
6 |
echo "<br />array_pad 还可以填充数组首部<br />"; |
7 |
$num = array_pad($num,-8,40); |
8 |
print_r($num); |
9 |
?> |
运行结果：
1 |
使用array_pad函数向数组尾部添加成员 |
2 |
Array ( [0] => 80 [1] => 120 [2] => 160 [3] => 200 ) |
3 |
array_pad 还可以填充数组首部 |
4 |
Array ( [0] => 40 [1] => 40 [2] => 40 [3] => 40 [4] => 80 [5] => 120 [6] => 160 [7] => 200 ) |
实例三：入栈操作追加（array_push）：
1 |
<?PHP |
2 |
$num = array(1=>80,2=>120,3=>160); |
3 |
array_push($num,200,240,280);//可以自己追加，直接加在数组结尾 |
4 |
print_r($num); |
5 |
?> |
运行结果：
1 |
Array ( [1] => 80 [2] => 120 [3] => 160 [4] => 200 [5] => 240 [6] => 280 ) |
实例四：array_unshift()在开头添加数组成员
1 |
<?PHP |
2 |
$num = array(1=>80,2=>120,3=>160); |
3 |
array_unshift($num,0,40);//可以自己追加，直接加在数组结尾 |
4 |
print_r($num); |
5 |
?> |
运行结果：
1 |
Array ( [0] => 0 [1] => 40 [2] => 80 [3] => 120 [4] => 160 ) |
注意：array_unshift()函数使用后数组的键值将会从0开始！
删减数组成员
实例一：unset()命令删除数组成员或数组：
01 |
<?PHP |
02 |
$num = array_fill(0,5,rand(1,10)); |
03 |
print_r($num); |
04 |
echo "<br />"; |
05 |
unset($num[4]); |
06 |
print_r($num); |
07 |
echo "<br />"; |
08 |
unset($num); |
09 |
if(is_array){ |
10 |
echo "unset命令不能删除整个数组"; |
11 |
}else{ |
12 |
echo "unset命令可以删除数组"; |
13 |
} |
14 |
?> |
运行结果：（运行出错及说明数组也被删除，不再存在）
1 |
Array ( [0] => 9 [1] => 9 [2] => 9 [3] => 9 [4] => 9 ) |
2 |
Array ( [0] => 9 [1] => 9 [2] => 9 [3] => 9 ) |
3 |
4 |
Notice: Use of undefined constant is_array - assumed 'is_array' in H:wampwww estingeditorplus est.php on line 21 |
5 |
unset命令不能删除整个数组 |
实例二：array_splice()函数删除数组成员
1 |
<?php |
2 |
$a=array("red", "green", "blue", "yellow"); |
3 |
count ($a); //得到4 |
4 |
array_splice($a,1,1); //删除第二个元素 |
5 |
count ($a); //得到3 |
6 |
echo $a[2]; //得到yellow |
7 |
echo $a[1]; //得到blue |
8 |
?> |
实例三：array_unique删除数组中的重复值：
1 |
<?php |
2 |
$a=array("red", "green", "blue", "yellow","blue","green"); |
3 |
$result = array_unique($a); |
4 |
print_r($result); |
5 |
?> |
运行结果：
1 |
Array ( [0] => red [1] => green [2] => blue [3] => yellow ) |
实例四：array_merge、array_merge_recursive合并数组
01 |
<?php |
02 |
$array1 = array("r"=>"red",1,2,3,4); |
03 |
$array2 = array("b"=>"blue",4=>5,6,7,8,9); |
04 |
$array3 = array("r"=>"read",4=>10,2=>11); |
05 |
$array4 = array( |
06 |
array(4=>10), |
07 |
array(7=>13) |
08 |
); |
09 |
$array5 = array( |
10 |
array(4=>11), |
11 |
array(6=>12) |
12 |
); |
13 |
$result = array_merge($array1,$array2,$array3,$array4,$array5); |
14 |
echo "<pre>"; |
15 |
print_r($result); |
16 |
echo "</pre>"; |
17 |
$result = array_merge_recursive($array1,$array2,$array3,$array4,$array5); |
18 |
echo "<pre>"; |
19 |
print_r ($result); |
20 |
echo "</pre>"; |
21 |
?> |
运行结果：
01 |
Array |
02 |
( |
03 |
[r] => read |
04 |
[0] => 1 |
05 |
[1] => 2 |
06 |
[2] => 3 |
07 |
[3] => 4 |
08 |
[b] => blue |
09 |
[4] => 5 |
10 |
[5] => 6 |
11 |
[6] => 7 |
12 |
[7] => 8 |
13 |
[8] => 9 |
14 |
[9] => 10 |
15 |
[10] => 11 |
16 |
[11] => Array |
17 |
( |
18 |
[4] => 10 |
19 |
) |
20 |
21 |
[12] => Array |
22 |
( |
23 |
[7] => 13 |
24 |
) |
25 |
26 |
[13] => Array |
27 |
( |
28 |
[4] => 11 |
29 |
) |
30 |
31 |
[14] => Array |
32 |
( |
33 |
[6] => 12 |
34 |
) |
35 |
36 |
) |
37 |
Array |
38 |
( |
39 |
[r] => Array |
40 |
( |
41 |
[0] => red |
42 |
[1] => read |
43 |
) |
44 |
45 |
[0] => 1 |
46 |
[1] => 2 |
47 |
[2] => 3 |
48 |
[3] => 4 |
49 |
[b] => blue |
50 |
[4] => 5 |
51 |
[5] => 6 |
52 |
[6] => 7 |
53 |
[7] => 8 |
54 |
[8] => 9 |
55 |
[9] => 10 |
56 |
[10] => 11 |
57 |
[11] => Array |
58 |
( |
59 |
[4] => 10 |
60 |
) |
61 |
62 |
[12] => Array |
63 |
( |
64 |
[7] => 13 |
65 |
) |
66 |
67 |
[13] => Array |
68 |
( |
69 |
[4] => 11 |
70 |
) |
71 |
72 |
[14] => Array |
73 |
( |
74 |
[6] => 12 |
75 |
) |
76 |
77 |
) |
注：1. array_merge的键名是数字的将重新建立索引；遇到相同的字符串键名时，后面的将覆盖前面的。 2. array_merge_recursive函数的作用是将相同字符串的键名单元整合成一个数组。
6. 数组的键值和值操作
实例一：in_array()检测数组中是否有某个值存在
1 |
<?php |
2 |
$array = range(0,9); |
3 |
if(in_array(9,$array)){ |
4 |
echo "数组中存在"; |
5 |
} |
6 |
?> |
运行结果：数组中存在
实例二：key()取得数组当前的键名：
1 |
<?php |
2 |
$array = range(0,9); |
3 |
$num = rand(0,8); |
4 |
while($num--) |
5 |
next($array); |
6 |
$key = key($array); |
7 |
echo $key; |
8 |
?> |
此实例结果为动态结果，范围（0-8），不做结果演示。
实例三：list()函数把数组中的值赋给指定变量：
01 |
<?PHP |
02 |
$staff = array( |
03 |
array("姓名","性别","年龄"), |
04 |
array("小张","男",24), |
05 |
array("小王","女",25), |
06 |
array("小李","男",23) |
07 |
); |
08 |
echo "<table border=2>"; |
09 |
while(list($keys,$value) = each($staff)){ |
10 |
list($name,$sex,$age) = $value; |
11 |
echo "<tr><td>$name</td><td>$sex</td><td>$age</td></tr>"; |
12 |
} |
13 |
echo "</table>"; |
14 |
?> |
实例四：array_flip()交换数组的键值和值:
1 |
<?PHP |
2 |
$array = array("red","blue","yellow","Black"); |
3 |
print_r($array); |
4 |
echo "<br />"; |
5 |
$array = array_flip($array); |
6 |
print_r($array); |
7 |
?> |
运行结果：
1 |
Array ( [0] => red [1] => blue [2] => yellow [3] => Black ) |
2 |
Array ( [red] => 0 [blue] => 1 [yellow] => 2 [Black] => 3 ) |
实例五：array_keys()、array_values()返回数组中所有的键值和值：
1 |
<?PHP |
2 |
$array = array("red","blue","yellow","Black"); |
3 |
$result = array_keys($array); |
4 |
print_r($result); |
5 |
echo "<br />"; |
6 |
$result = array_values($array); |
7 |
print_r($result); |
8 |
?> |
运行结果：
1 |
Array ( [0] => 0 [1] => 1 [2] => 2 [3] => 3 ) |
2 |
Array ( [0] => red [1] => blue [2] => yellow [3] => Black ) |
实例六：array_search()搜索数值:
1 |
<?PHP |
2 |
$array = array("red","blue","yellow","Black"); |
3 |
$result = array_search("red",$array); |
4 |
if(($result === NULL)){ |
5 |
echo "不存在数值red"; |
6 |
}else{ |
7 |
echo "存在数值 $result"; |
8 |
} |
9 |
?> |
结果：存在数值 0
函数array_search()返回的值可能为false或0或NULL，所以在判断时注意要用"==="
7. 数组的排序
实例一：sort()、rsort()/asort()、arsort()对数组排序：
1 |
<?PHP |
2 |
$array = array("b","c","d","a"); |
3 |
sort($array);//从低到高排序 |
4 |
print_r($array); |
5 |
echo "<br />"; |
6 |
rsort($array);//逆向排序 |
7 |
print_r($array); |
8 |
?> |
结果：
1 |
Array ( [0] => a [1] => b [2] => c [3] => d ) |
2 |
Array ( [0] => d [1] => c [2] => b [3] => a ) |
sort()、rsort()函数对数组进行从低到高的排序，返回结果为bool值；
asort()、arsort()函数是保留键值的排序，排序后键值不重新索引。
实例二：将数组顺序打乱——shuffle()函数：
1 |
<?PHP |
2 |
$array = array("a","b","c","d"); |
3 |
shuffle($array);//从低到高排序 |
4 |
print_r($array); |
5 |
?> |
结果为动态结果：
1 |
Array ( [0] => c [1] => a [2] => d [3] => b ) |
shuffle的结果有点随机的意味，每次刷新都不一样。
实例三：array_reverse()数组反向：
1 |
<?PHP |
2 |
$array = array("d","b","a","c"); |
3 |
$array = array_reverse($array);//从低到高排序 |
4 |
print_r($array); |
5 |
?> |
运行结果：
1 |
Array ( [0] => c [1] => a [2] => b [3] => d ) |
实例四：自然排序算法——natsort()和natcasesort();
1 |
<?PHP |
2 |
$array = array("sort2","Sort5","sort1","sort4"); |
3 |
natsort($array);//从低到高排序 |
4 |
print_r($array); |
5 |
echo "<br />"; |
6 |
natcasesort($array); |
7 |
print_r($array); |
8 |
?> |
结果：
1 |
Array ( [1] => Sort5 [2] => sort1 [0] => sort2 [3] => sort4 ) |
2 |
Array ( [2] => sort1 [0] => sort2 [3] => sort4 [1] => Sort5 ) |
natsort()、natcasesort()对数组进行自然排序，就是使用数字的正常排序算法。natcasesort会忽略大小写。
实例五：对数组进行键值排序ksort():
1 |
<?PHP |
2 |
$array = array(1=>"sort2",4=>"Sort5",2=>"sort1",3=>"sort4"); |
3 |
ksort($array);//从低到高排序 |
4 |
print_r($array); |
5 |
?> |
结果：
1 |
Array ( [1] => sort2 [2] => sort1 [3] => sort4 [4] => Sort5 ) |
注意：ksort()函数重新建立了索引。
8. 数组的其他用法
01 |
cout($array) --------统计数组的单元个数 |
02 |
array_diff($array1,$array2)----------统计数组之间的不同点，返回第一个数组中有而第二个数组中没有的。 |
03 |
array_diff_assoc($array1,$array2)---------同array_diff()，只是它对键值也比较 |
04 |
array_diff_key($array1,$array2)------------比较键值 |
05 |
array_product($array)-----------返回数组的所有数的乘积 |
06 |
array_sum($array)--------------所有数值的和 |
07 |
array_rand($array,$n)----------在$array数组中取出$n个数值，返回数组 |
08 |
array_intersect($array1,$array2)----------------取得两个数组的交集 |
09 |
array_intersect_assoc($array1,$array2)---------------在array_intersect 的基础上进行键值比较 |
10 |
array_intersect_key($array1,$array2)-----------------比较两个数组键值的交集 |
总结
数组的使用在PHP中至关重要，由于PHP没有指针，所以数组承担了很大的数据操作任务。学好数组，才能把PHP应用的得心应手，这里所列均是常用的PHP数组相关的函数及用法，欢迎一起学习！