在php中数组是我们开发应用中不可少的了部份,下面我来把我自己学习php数组的一些操作给各位同学分享一下,希望有需要了解的同学可进入参考。
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。
. 数组定义
数组的定义使用 array()方式定义,可以定义空数组,代码如下:
- <?php
- $number = array(1,3,5,7,9);
-
- $result = array();
- $color =array("red","blue","green");
-
- $language = (1=>"English",3=>"Chinese",5=>"Franch");
-
- $two = array(
- "color"=>array("red","blue"),
- "week"=>array("Monday","Friday")
- );
- ?>
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 $... ] )。
实例代码如下:
- <?php
- $number = "1,3,5,7,9";
- $string = "I'm PHPer";
- $array = array("And","You?");
- $newArray = compact("number","string","array");
- print_r ($newArray);
- ?>
ompact()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:
- Array (
- [number] => 1,3,5,7,9
- [string] => I'm PHPer
- [array] => Array ( [0] => And [1] => You? )
- )
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 )
代码如下:
- <?php
- $number = array("1","3","5","7","9");
- $array = array("I","Am","A","PHP","er");
- $newArray = array_combine($number,$array);
- print_r ($newArray);
- ?>
array_combine函数不多说了,谁看了都明白。
运行结果:
Array ( [1] => I [3] => Am [5] => A [7] => PHP [9] => er )
range()
range()函数——创建指定范围的数组,代码如下:
- <?php
- $array1 = range(0,100,10);
- print_r($array1);
- echo"";
- $array2 = range("A","Z");
- print_r($array2);
- echo "";
- $array3 = range("z","a");
- print_r($array3);
- ?>
array_fill()
array_fill()函数——填充数组函数,代码如下:
- <?php
- $array = range(1,10);
- $fillarray = range("a","d");
- $arrayFilled = array_fill(0,5,$fillarray);
- echo "
- ";
- print_r ($arrayFilled);
- echo "";
- $keys = array("string","2",9,"SDK","PK");
- $array2 = array_fill_keys($keys,"testing");
- echo "
- ";
- print_r ($array2);
- echo "";
- ?>
运行结果:
- Array
- (
- [0] => Array
- (
- [0] => a
- [1] => b
- [2] => c
- [3] => d
- )
- [1] => Array
- (
- [0] => a
- [1] => b
- [2] => c
- [3] => d
- )
- [2] => Array
- (
- [0] => a
- [1] => b
- [2] => c
- [3] => d
- )
- [3] => Array
- (
- [0] => a
- [1] => b
- [2] => c
- [3] => d
- )
- [4] => Array
- (
- [0] => a
- [1] => b
- [2] => c
- [3] => d
- )
- )
- Array
- (
- [string] => testing
- [2] => testing
- [9] => testing
- [SDK] => testing
- [PK] => testing
- )
数组的遍历
foreach遍历
foreach (array_expression as $value){}
foreach (array_expression as $key => $value){}
实例代码如下:
- $speed = array(50,120,180,240,380);
- foreach($speed as $keys=>$values){
- echo $keys."=>".$values."";
- }
运行结果:
- 0=>50
- 1=>120
- 2=>180
- 3=>240
- 4=>380
while循环遍历
while循环遍历一般结合list函数,以下是实例,代码如下:
- <?php
- $staff = array(
- array("姓名","性别","年龄"),
- array("小张","男",24),
- array("小王","女",25),
- array("小李","男",23)
- );
- echo "";
- while(list($keys,$value) = each($staff)){
- list($name,$sex,$age) = $value;
- echo "$name$sex$age";
- }
- echo "";
- ?>
for循环遍历
实例代码如下:
- <?php
- $speed = range(0,220,20);
- for($i =0;$i<count($speed);$i++) {
- echo $speed[$i]." ";
- }
- ?>
运行结果:0 20 40 60 80 100 120 140 160 180 200 220
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,代码如下:
- <?php
- $speed = range(0,220,20);
- echo current($speed);
- $i = rand(1,11);
- while($i--){
- next($speed);
- }
- echo current($speed);
- echo "";
- echo prev($speed);
- echo "";
- echo reset($speed);
- echo "";
- echo end($speed);
- echo "";
- ?>
运行结果:
0220 200 0 220
实例二:each函数指针操作,代码如下:
- <?php
- $speed = range(0,200,40);
- echo "each实现指针下移 ";
- echo "0挡的速度是".current(each($speed))."";
- echo "1挡的速度是".current(each($speed))."";
- echo "2挡的速度是".current(each($speed))."";
- echo "3挡的速度是".current(each($speed))."";
- echo "4挡的速度是".current(each($speed))."";
- echo "5挡的速度是".current(each($speed))."";
- echo "使用each函数实现数组指针的移动,进行数组遍历 ";
- reset($speed);
- while(list($key,$value)=each($speed)){
- echo $key."=>".$value."";
- }
- ?>
运行结果:
each实现指针下移
0挡的速度是0
1挡的速度是40
2挡的速度是80
3挡的速度是120
4挡的速度是160
5挡的速度是200
使用each函数实现数组指针的移动,进行数组遍历
- 0=>0
- 1=>40
- 2=>80
- 3=>120
- 4=>160
- 5=>200
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,实例代码如下:
- <?php
- $num = array(1=>80,2=>120,3=>160);
- echo "使用表达式添加数组成员";
- $num[]=240;
- print_r($num);
- ?>
运行结果:
使用表达式添加数组成员
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,代码如下:
- <?php
- $num = array(1=>80,2=>120,3=>160);
- $num = array_pad($num,4,200);
- echo "使用array_pad函数向数组尾部添加成员";
- print_r($num);
- echo "array_pad 还可以填充数组首部";
- $num = array_pad($num,-8,40);
- print_r($num);
- ?>
运行结果:
使用array_pad函数向数组尾部添加成员
Array ( [0] => 80 [1] => 120 [2] => 160 [3] => 200 )
array_pad 还可以填充数组首部
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),代码如下:
- <?php
- $num = array(1=>80,2=>120,3=>160);
- array_push($num,200,240,280);
- print_r($num);
- ?>
运行结果:
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,代码如下:
- <?php
- $num = array(1=>80,2=>120,3=>160);
- array_unshift($num,0,40);
- print_r($num);
- ?>
运行结果:
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,代码如下:
- <?php
- $num = array_fill(0,5,rand(1,10));
- print_r($num);
- echo "";
- unset($num[4]);
- print_r($num);
- echo "";
- unset($num);
- if(is_array){
- echo "unset命令不能删除整个数组";
- }else{
- echo "unset命令可以删除数组";
- }
- ?>
运行结果:(运行出错及说明数组也被删除,不再存在)
Array ( [0] => 9 [1] => 9 [2] => 9 [3] => 9 [4] => 9 )
Array ( [0] => 9 [1] => 9 [2] => 9 [3] => 9 )
unset命令不能删除整个数组
实例二:array_splice()函数删除数组成员,代码如下:
- $a=array("red", "green", "blue", "yellow");
- count ($a);
- array_splice($a,1,1);
- count ($a);
- echo $a[2];
- echo $a[1];
实例三:array_unique删除数组中的重复值,代码如下:
- <?php
- $a=array("red", "green", "blue", "yellow","blue","green");
- $result = array_unique($a);
- print_r($result);
- ?>
运行结果:
Array ( [0] => red [1] => green [2] => blue [3] => yellow )
实例四:array_merge、array_merge_recursive合并数组,代码如下:
- <?php
- $array1 = array("r"=>"red",1,2,3,4);
- $array2 = array("b"=>"blue",4=>5,6,7,8,9);
- $array3 = array("r"=>"read",4=>10,2=>11);
- $array4 = array(
- array(4=>10),
- array(7=>13)
- );
- $array5 = array(
- array(4=>11),
- array(6=>12)
- );
- $result = array_merge($array1,$array2,$array3,$array4,$array5);
- echo "
- ";
- print_r($result);
- echo "";
- $result = array_merge_recursive($array1,$array2,$array3,$array4,$array5);
- echo "
- ";
- print_r ($result);
- echo "";
- ?>
运行结果:
- Array
- (
- [r] => read
- [0] => 1
- [1] => 2
- [2] => 3
- [3] => 4
- [b] => blue
- [4] => 5
- [5] => 6
- [6] => 7
- [7] => 8
- [8] => 9
- [9] => 10
- [10] => 11
- [11] => Array
- (
- [4] => 10
- )
- [12] => Array
- (
- [7] => 13
- )
- [13] => Array
- (
- [4] => 11
- )
- [14] => Array
- (
- [6] => 12
- )
- )
- Array
- (
- [r] => Array
- (
- [0] => red
- [1] => read
- )
- [0] => 1
- [1] => 2
- [2] => 3
- [3] => 4
- [b] => blue
- [4] => 5
- [5] => 6
- [6] => 7
- [7] => 8
- [8] => 9
- [9] => 10
- [10] => 11
- [11] => Array
- (
- [4] => 10
- )
- [12] => Array
- (
- [7] => 13
- )
- [13] => Array
- (
- [4] => 11
- )
- [14] => Array
- (
- [6] => 12
- )
- )
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。
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,代码如下:
- $array = range(0,9);
- if(in_array(9,$array)){
- echo "数组中存在";
- }
运行结果:数组中存在
实例二:key()取得数组当前的键名,代码如下:
- <?php
- $array = range(0,9);
- $num = rand(0,8);
- while($num--)
- next($array);
- $key = key($array);
- echo $key;
- ?>
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,代码如下:
- <?Php
- $staff = array(
- array("姓名","性别","年龄"),
- array("小张","男",24),
- array("小王","女",25),
- array("小李","男",23)
- );
- echo "";
- while(list($keys,$value) = each($staff)){
- list($name,$sex,$age) = $value;
- echo "$name$sex$age";
- }
- echo "";
- ?>
实例四:array_flip()交换数组的键值和值,代码如下:
- <?Php
- $array = array("red","blue","yellow","Black");
- print_r($array);
- echo "";
- $array = array_flip($array);
- print_r($array);
- ?>
-
-
-
代码如下:
- <?php
- $array = array("red","blue","yellow","Black");
- $result = array_keys($array);
- print_r($result);
- echo "";
- $result = array_values($array);
- print_r($result);
- ?>
-
-
-
实例六:array_search()搜索数值,代码如下:
- <?php
- $array = array("red","blue","yellow","Black");
- $result = array_search("red",$array);
- if(($result === NULL)){
- echo "不存在数值red";
- }else{
- echo "存在数值 $result";
- }
- ?>
-
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"==="
数组的排序
实例一:sort()、rsort()/asort()、arsort()对数组排序,代码如下:
- <?php
- $array = array("b","c","d","a");
- sort($array);
- print_r($array);
- echo "";
- rsort($array);
- print_r($array);
- ?>
-
-
-
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,代码如下:
- <?php
- $array = array("a","b","c","d");
- shuffle($array);
- print_r($array);
- ?>
-
-
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,代码如下:
- <?php
- $array = array("d","b","a","c");
- $array = array_reverse($array);
- print_r($array);
- ?>
-
-
实例四:自然排序算法——natsort()和natcasesort();代码如下:
- <?php
- $array = array("sort2","Sort5","sort1","sort4");
- natsort($array);
- print_r($array);
- echo "";
- natcasesort($array);
- print_r($array);
- ?>
-
-
-
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(),代码如下:
- <?php
- $array = array(1=>"sort2",4=>"Sort5",2=>"sort1",3=>"sort4");
- ksort($array);
- print_r($array);
- ?>
-
-
注意:ksort()函数重新建立了索引。
数组的其他用法
代码如下:
- array = array ('A', 'B', 'C' );
-
- array_unshift ( $array, 'E', 'F', 'G' );
- var_dump ( $array );
- $array = array ('A', 'B', 'C' );
-
- array_push ( $array, 'E', 'F', 'G' );
- var_dump ( $array );
- $array = array ('A', 'B', 'C' );
-
- array_shift ( $array );
- var_dump ( $array );
- $array = array ('A', 'B', 'C' );
-
- array_pop ( $array );
- var_dump ( $array );
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