"Chinese",5=>"Franch"); //定义二维数组 $two = array( "color"=>array("red","blue"), //用逗号结尾 "week"=>array("Monday","Friday")"> 跳转到主内容
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php 数组应用详解

php 数组使用详解 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…… 一、数组定义: 数组的定义使用 array()方式定义,可以定义空数组: .foreach遍历: 复制代码 代码如下: php
"English",3=>"Chinese",5=>"Franch"); //定义二维数组 $two = array( "color"=>array("red","blue"), //用逗号结尾 "week"=>array("Monday","Friday") //最后一句没有标点 ); ?> 二、创建数组: 创建数组包含的函数有compact()、 1.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 $... ] ) 复制代码 代码如下: PHP
compact()函数用于将两个或多个变量转换为数组,当然也包含数组变量。其参数是变量的名称而非带有$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: 复制代码 代码如下: Array ( [number] => 1,3,5,7,9 [string] => I"m PHPer [array] => Array ( [0] => And [1] => You? ) ) 2.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 $values ) 复制代码 代码如下: PHP
array_combine函数不多说了,谁看了都明白 运行结果: Array ( [1] => I [3] => Am [5] => A [7] => PHP [9] => er ) 3.range()函数——创建指定范围的数组:       不多说了,直接上实例—— 立即学习 “ PHP免费学习笔记(深入) ”; 复制代码 代码如下: PHP
range()函数的默认步进值是1! 运行结果: 复制代码 代码如下: Array ( [0] => 0 [1] => 10 [2] => 20 [3] => 30 [4] => 40 [5] => 50 [6] => 60 [7] => 70 [8] => 80 [9] => 90 [10] => 100 ) Array ( [0] => A [1] => B [2] => C [3] => D [4] => E [5] => F [6] => G [7] => H [8] => I [9] => J [10] => K [11] => L [12] => M [13] => N [14] => O [15] => P [16] => Q [17] => R [18] => S [19] => T [20] => U [21] => V [22] => W [23] => X [24] => Y [25] => Z ) Array ( [0] => z [1] => y [2] => x [3] => w [4] => v [5] => u [6] => t [7] => s [8] => r [9] => q [10] => p [11] => o [12] => n [13] => m [14] => l [15] => k [16] => j [17] => i [18] => h [19] => g [20] => f [21] => e [22] => d [23] => c [24] => b [25] => a ) 4.array_fill()函数——填充数组函数: 复制代码 代码如下: PHP
";
print_r ($arrayFilled);
echo "
"; $keys = array("string","2",9,"SDK","PK"); $array2 = array_fill_keys($keys,"testing"); echo "
";
print_r ($array2);
echo "
"; ?> 运行结果: 复制代码 代码如下: 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 ) 三、数组的遍历: 1.foreach遍历:       foreach (array_expression as $value){} foreach (array_expression as $key => $value){} 闲话少说,上实例: 复制代码 代码如下: PHP
$values){ echo $keys."=>".$values." "; } ?> 运行结果: 复制代码 代码如下: 0=>50 1=>120 2=>180 3=>240 4=>380 2.while循环遍历: while循环遍历一般结合list函数,以下是实例 复制代码 代码如下: PHP
运行结果: 姓名性别年龄小张男24小王女25小李男23 3.for循环遍历: 复制代码 代码如下: PHP
运行结果:复制代码代码如下:0 20 40 60 80 100 120 140 160 180 200 220四、数组的指针操作:涉及函数包括reset、prev、end、next、current、each实例一:复制代码代码如下:$speed = range(0,220,20);echo current($speed);//输出当前位置的值(在数组的开头位置)$i = rand(1,11);while($i--){next($speed);//指针从当前位置向后移动一位}echo current($speed);//输出当前位置的值echo "";echo prev($speed);//输出前一位置数组值echo "";echo reset($speed);//重置数组的指针,将指针指向起始位置echo "";echo end($speed);//输出最后位置的数组值echo "";?>运行结果:复制代码代码如下:02202000220实例二:each函数指针操作复制代码代码如下:$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($speed);//这里是将数组指针指向数组首while(list($key,$value)=each($speed)){echo $key."=>".$value."";}?>运行结果:复制代码代码如下:each实现指针下移0挡的速度是01挡的速度是402挡的速度是803挡的速度是1204挡的速度是1605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=>01=>402=>803=>1204=>1605=>200五、数组的增添删改操作:1.增添数组成员:实例一:$num[] = value直接赋值追加到数组末尾:复制代码代码如下:$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复制代码代码如下:$num = array(1=>80,2=>120,3=>160);$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($num);?>运行结果:复制代码代码如下:使用array_pad函数向数组尾部添加成员Array ( [0] => 80 [1] => 120 [2] => 160 [3] => 200 ) array_pad 还可以填充数组首部Array ( [0] => 40 [1] => 40 [2] => 40 [3] => 40 [4] => 80 [5] => 120 [6] => 160 [7] => 200 )实例三:入栈操作追加(array_push):复制代码代码如下:$num = array(1=>80,2=>120,3=>160);array_push($num,200,240,280);//可以自己追加,直接加在数组结尾print_r($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复制代码代码如下:$num = array(1=>80,2=>120,3=>160);array_unshift($num,0,40);//可以自己追加,直接加在数组结尾print_r($num);?>运行结果:Array ( [0] => 0 [1] => 40 [2] => 80 [3] => 120 [4] => 160 )注意:array_unshift()函数使用后数组的键值将会从0开始!2.删减数组成员:实例一:unset()命令删除数组成员或数组:复制代码代码如下:$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)复制代码代码如下:Array ( [0] => 9 [1] => 9 [2] => 9 [3] => 9 [4] => 9 )Array ( [0] => 9 [1] => 9 [2] => 9 [3] => 9 )Notice: Use of undefined constant is_array - assumed "is_array" in H:\wamp\www\testing\editorplus\test.php on line 21unset命令不能删除整个数组实例二:array_splice()函数删除数组成员复制代码代码如下:$a=array("red", "green", "blue", "yellow");count ($a); //得到4array_splice($a,1,1); //删除第二个元素count ($a); //得到3echo $a[2]; //得到yellowecho $a[1]; //得到blue?>实例三:array_unique删除数组中的重复值:复制代码代码如下:$a=array("red", "green", "blue", "yellow","blue","green");$result = array_unique($a);print_r($result);?>运行结果:Array ( [0] => red [1] => green [2] => blue [3] => yellow )实例四:array_merge、array_merge_recursive合并数组复制代码代码如下:$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:复制代码代码如下: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。六、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复制代码代码如下:$array = range(0,9);if(in_array(9,$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:复制代码代码如下:$array = range(0,9);$num = rand(0,8);while($num--)next($array);$key = key($array);echo $key;?>此实例结果为动态结果,范围(0-8),不做结果演示。实例三:list()函数把数组中的值赋给指定变量:复制代码代码如下:$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 "";?>运行结果:实例四:array_flip()交换数组的键值和值:复制代码代码如下:$array = array("red","blue","yellow","Black");print_r($array);echo "";$array = array_flip($array);print_r($array);?>运行结果:复制代码代码如下:Array ( [0] => red [1] => blue [2] => yellow [3] => Black )Array ( [red] => 0 [blue] => 1 [yellow] => 2 [Black] => 3 )实例五:array_keys()、array_values()返回数组中所有的键值和值:复制代码代码如下:$array = array("red","blue","yellow","Black");$result = array_keys($array);print_r($result);echo "";$result = array_values($array);print_r($result);?>运行结果:复制代码代码如下:Array ( [0] => 0 [1] => 1 [2] => 2 [3] => 3 )Array ( [0] => red [1] => blue [2] => yellow [3] => Black )实例六:array_search()搜索数值:复制代码代码如下:$array = array("red","blue","yellow","Black");$result = array_search("red",$array);if(($result === NULL)){echo "不存在数值red";}else{echo "存在数值 $result";}?>结果:存在数值 0函数array_search()返回的值可能为false或0或NULL,所以在判断时注意要用"==="七、数组的排序:实例一:sort()、rsort()/asort()、arsort()对数组排序:复制代码代码如下:$array = array("b","c","d","a");sort($array);//从低到高排序print_r($array);echo "";rsort($array);//逆向排序print_r($array);?>结果:Array ( [0] => a [1] => b [2] => c [3] => d )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:复制代码代码如下:$array = array("a","b","c","d");shuffle($array);//从低到高排序print_r($array);?>结果为动态结果:Array ( [0] => c [1] => a [2] => d [3] => b )shuffle的结果有点随机的意味,每次刷新都不一样。实例三:array_reverse()数组反向:复制代码代码如下:$array = array("d","b","a","c");$array = array_reverse($array);//从低到高排序print_r($array);?>运行结果:Array ( [0] => c [1] => a [2] => b [3] => d )实例四:自然排序算法——natsort()和natcasesort();复制代码代码如下:$array = array("sort2","Sort5","sort1","sort4");natsort($array);//从低到高排序print_r($array);echo "";natcasesort($array);print_r($array);?>结果:Array ( [1] => Sort5 [2] => sort1 [0] => sort2 [3] => sort4 )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():复制代码代码如下:$array = array(1=>"sort2",4=>"Sort5",2=>"sort1",3=>"sort4");ksort($array);//从低到高排序print_r($array);?>结果:Array ( [1] => sort2 [2] => sort1 [3] => sort4 [4] => Sort5 )注意:ksort()函数重新建立了索引。八、数组的其他用法:cout($array) --------统计数组的单元个数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。array_diff_assoc($array1,$array2)---------同array_diff(),只是它对键值也比较array_diff_key($array1,$array2)------------比较键值array_product($array)-----------返回数组的所有数的乘积array_sum($array)--------------所有数值的和array_rand($array,$n)----------在$array数组中取出$n个数值,返回数组array_intersect($array1,$array2)----------------取得两个数组的交集array_intersect_assoc($array1,$array2)---------------在array_intersect 的基础上进行键值比较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!

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