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: <div class="codetitle"><a style="CURSOR: pointer" data="99323" class="copybut" id="copybut99323" onclick="doCopy('code99323')"> 代码如下:<div class="codebody" id="code99323"> <?php $number = array(1,3,5,7,9); //定义空数组 $result = array(); $color =array("red","blue","green"); //自定义键值 $language = (1=>"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 ); ?> 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 $... ] )。 <div class="codetitle"><a style="CURSOR: pointer" data="91037" class="copybut" id="copybut91037" onclick="doCopy('code91037')"> 代码如下:<div class="codebody" id="code91037"> <?PHP $number = "1,9"; $string = "I'm PHPer"; $array = array("And","You?"); $newArray = compact("number","string","array"); print_r ($newArray); ?> 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: <div class="codetitle"><a style="CURSOR: pointer" data="69011" class="copybut" id="copybut69011" onclick="doCopy('code69011')"> 代码如下:<div class="codebody" id="code69011"> Array ( [number] => 1,9 [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 ) <div class="codetitle"><a style="CURSOR: pointer" data="8532" class="copybut" id="copybut8532" onclick="doCopy('code8532')"> 代码如下:<div class="codebody" id="code8532"> <?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: <div class="codetitle"><a style="CURSOR: pointer" data="89969" class="copybut" id="copybut89969" onclick="doCopy('code89969')"> 代码如下:<div class="codebody" id="code89969"><?PHP $array1 = range(0,100,10);//0为起始值,100为结束值,10为步进值(默认步进值为1). print_r($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: <div class="codetitle"><a style="CURSOR: pointer" data="72215" class="copybut" id="copybut72215" onclick="doCopy('code72215')"> 代码如下:<div class="codebody" id="code72215"> <?PHP $array = range(1,10); $fillarray = range("a","d"); $arrayFilled = array_fill(0,$fillarray);//这里的$fillarray可以是字符串,如"test". echo ""; print_r ($arrayFilled); echo " "; $keys = array("string","2",9,"SDK","PK"); $array2 = array_fill_keys($keys,"testing"); echo ""; print_r ($array2); echo " "; ?> 运行结果: <div class="codetitle"><a style="CURSOR: pointer" data="98919" class="copybut" id="copybut98919" onclick="doCopy('code98919')"> 代码如下:<div class="codebody" id="code98919"> 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 ) 3. 数组的遍历 foreach遍历 foreach (array_expression as $value){} foreach (array_expression as $key => $value){} <div class="codetitle"><a style="CURSOR: pointer" data="18809" class="copybut" id="copybut18809" onclick="doCopy('code18809')"> 代码如下:<div class="codebody" id="code18809"> <?PHP $speed = array(50,120,180,240,380); foreach($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 <div class="codetitle"><a style="CURSOR: pointer" data="85697" class="copybut" id="copybut85697" onclick="doCopy('code85697')"> 代码如下:<div class="codebody" id="code85697"> <?PHP $staff = array( array("姓名","性别","年龄"), array("小张","男",24), array("小王","女",25), array("小李",23) ); echo ""; while(list($keys,$value) = each($staff)){ list($name,$sex,$age) = $value; echo "<tr><td>$name</td><td>$sex</td><td>$age</td></tr>"; } echo "</table>"; ?> for循环遍历 <div class="codetitle"><a style="CURSOR: pointer" data="85033" class="copybut" id="copybut85033" onclick="doCopy('code85033')"> 代码如下:<div class="codebody" id="code85033"><?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 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 <div class="codetitle"><a style="CURSOR: pointer" data="60466" class="copybut" id="copybut60466" onclick="doCopy('code60466')"> 代码如下:<div class="codebody" id="code60466"> <?PHP $speed = range(0,20); echo current($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: 0220 200 0 220 实例二:each函数指针操作 <div class="codetitle"><a style="CURSOR: pointer" data="34167" class="copybut" id="copybut34167" onclick="doCopy('code34167')"> 代码如下:<div class="codebody" id="code34167"> <?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);//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: <div class="codetitle"><a style="CURSOR: pointer" data="86506" class="copybut" id="copybut86506" onclick="doCopy('code86506')"> 代码如下:<div class="codebody" id="code86506"> 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 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: [code]<?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 <div class="codetitle"><a style="CURSOR: pointer" data="29490" class="copybut" id="copybut29490" onclick="doCopy('code29490')"> 代码如下:<div class="codebody" id="code29490"> <?PHP $num = array(1=>80,3=>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): <div class="codetitle"><a style="CURSOR: pointer" data="53653" class="copybut" id="copybut53653" onclick="doCopy('code53653')"> 代码如下:<div class="codebody" id="code53653"> <?PHP $num = array(1=>80,3=>160); array_push($num,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 <div class="codetitle"><a style="CURSOR: pointer" data="81165" class="copybut" id="copybut81165" onclick="doCopy('code81165')"> 代码如下:<div class="codebody" id="code81165"> <?PHP $num = array(1=>80,3=>160); array_unshift($num,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! 删减数组成员 实例一:unset()命令删除数组成员或数组: <div class="codetitle"><a style="CURSOR: pointer" data="45512" class="copybut" id="copybut45512" onclick="doCopy('code45512')"> 代码如下:<div class="codebody" id="code45512"> <?PHP $num = array_fill(0,rand(1,10)); print_r($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 ) Notice: Use of undefined constant is_array - assumed 'is_array' in H:wampwwwtestingeditorplustest.php on line 21 unset命令不能删除整个数组 实例二:array_splice()函数删除数组成员 <div class="codetitle"><a style="CURSOR: pointer" data="79029" class="copybut" id="copybut79029" onclick="doCopy('code79029')"> 代码如下:<div class="codebody" id="code79029"><?php $a=array("red","green","yellow"); count ($a); //得到4 array_splice($a,1,1); //删除第二个元素 count ($a); //得到3 echo $a[2]; //得到yellow echo $a[1]; //得到blue ?> 实例三:array_unique删除数组中的重复值: <div class="codetitle"><a style="CURSOR: pointer" data="51921" class="copybut" id="copybut51921" onclick="doCopy('code51921')"> 代码如下:<div class="codebody" id="code51921"> <?php $a=array("red","yellow","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 <div class="codetitle"><a style="CURSOR: pointer" data="59802" class="copybut" id="copybut59802" onclick="doCopy('code59802')"> 代码如下:<div class="codebody" id="code59802"> <?php $array1 = array("r"=>"red",2,4); $array2 = array("b"=>"blue",4=>5,6,8,9); $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,$array5); echo ""; print_r ($result); echo " "; ?> 运行结果: <div class="codetitle"><a style="CURSOR: pointer" data="9600" class="copybut" id="copybut9600" onclick="doCopy('code9600')"> 代码如下:<div class="codebody" id="code9600"> 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。 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 <div class="codetitle"><a style="CURSOR: pointer" data="86765" class="copybut" id="copybut86765" onclick="doCopy('code86765')"> 代码如下:<div class="codebody" id="code86765"> <?php $array = range(0,9); if(in_array(9,$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: <div class="codetitle"><a style="CURSOR: pointer" data="81829" class="copybut" id="copybut81829" onclick="doCopy('code81829')"> 代码如下:<div class="codebody" id="code81829"> <?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: <div class="codetitle"><a style="CURSOR: pointer" data="85697" class="copybut" id="copybut85697" onclick="doCopy('code85697')"> 代码如下:<div class="codebody" id="code85697"> <?PHP $staff = array( array("姓名",$age) = $value; echo "<tr><td>$name</td><td>$sex</td><td>$age</td></tr>"; } echo "</table>"; ?> 实例四:array_flip()交换数组的键值和值: <div class="codetitle"><a style="CURSOR: pointer" data="5327" class="copybut" id="copybut5327" onclick="doCopy('code5327')"> 代码如下:<div class="codebody" id="code5327"> <?PHP $array = array("red","Black"); print_r($array); echo " "; $array = array_flip($array); print_r($array); ?> 运行结果: Array ( [0] => red [1] => blue [2] => yellow [3] => Black ) Array ( [red] => 0 [blue] => 1 [yellow] => 2 [Black] => 3 ) <div class="codetitle"><a style="CURSOR: pointer" data="99582" class="copybut" id="copybut99582" onclick="doCopy('code99582')"> 代码如下:<div class="codebody" id="code99582"> <?PHP $array = array("red","Black"); $result = array_keys($array); print_r($result); echo " "; $result = array_values($array); print_r($result); ?> 运行结果: 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: <div class="codetitle"><a style="CURSOR: pointer" data="43376" class="copybut" id="copybut43376" onclick="doCopy('code43376')"> 代码如下:<div class="codebody" id="code43376"> <?PHP $array = array("red","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"===" 7. 数组的排序 实例一:sort()、rsort()/asort()、arsort()对数组排序: <div class="codetitle"><a style="CURSOR: pointer" data="85437" class="copybut" id="copybut85437" onclick="doCopy('code85437')"> 代码如下:<div class="codebody" id="code85437"> <?PHP $array = array("b","c","d","a"); sort($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: <div class="codetitle"><a style="CURSOR: pointer" data="32694" class="copybut" id="copybut32694" onclick="doCopy('code32694')"> 代码如下:<div class="codebody" id="code32694"> <?PHP $array = array("a","b","d"); shuffle($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: <div class="codetitle"><a style="CURSOR: pointer" data="44039" class="copybut" id="copybut44039" onclick="doCopy('code44039')"> 代码如下:<div class="codebody" id="code44039"> <?PHP $array = array("d","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(); <div class="codetitle"><a style="CURSOR: pointer" data="36562" class="copybut" id="copybut36562" onclick="doCopy('code36562')"> 代码如下:<div class="codebody" id="code36562"> <?PHP $array = array("sort2","Sort5","sort1","sort4"); natsort($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(): <div class="codetitle"><a style="CURSOR: pointer" data="58993" class="copybut" id="copybut58993" onclick="doCopy('code58993')"> 代码如下:<div class="codebody" id="code58993"> <?PHP $array = array(1=>"sort2",4=>"Sort5",2=>"sort1",3=>"sort4"); ksort($array);//从低到高排序 print_r($array); ?> 结果: Array ( [1] => sort2 [2] => sort1 [3] => sort4 [4] => Sort5 ) 注意:ksort()函数重新建立了索引。 8. 数组的其他用法 <div class="codetitle"><a style="CURSOR: pointer" data="65143" class="copybut" id="copybut65143" onclick="doCopy('code65143')"> 代码如下:<div class="codebody" id="code65143"> cout($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! (编辑:李大同)
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