PHP之数组学习
2015-01-24信息快讯网
对于网页编程来说,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
今天学习了数组,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……一、数组定义:
数组的定义使用 array()方式定义,可以定义空数组:
<?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 ); ?>
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 $... ] )
<?PHP $number = "1,3,5,7,9"; $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:
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 )
<?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 )
3.range()函数――创建指定范围的数组:
不多说了,直接上实例――
<?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"<br />"; $array2 = range("A","Z"); print_r($array2); echo "<br />"; $array3 = range("z","a"); print_r($array3); ?>
range()函数的默认步进值是1!
运行结果:
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:
<?PHP $array = range(1,10); $fillarray = range("a","d"); $arrayFilled = array_fill(0,5,$fillarray);//这里的$fillarray可以是字符串,如"test". echo "<pre>"; print_r ($arrayFilled); echo "</pre>"; $keys = array("string","2",9,"SDK","PK"); $array2 = array_fill_keys($keys,"testing"); echo "<pre>"; print_r ($array2); echo "</pre>"; ?>
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 )
二、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:
<?PHP $speed = array(50,120,180,240,380); foreach($speed as $keys=>$values){ echo $keys."=>".$values."<br />"; } ?>
运行结果:
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
<?PHP $staff = array( array("姓名","性别","年龄"), array("小张","男",24), array("小王","女",25), array("小李","男",23) ); echo "<table border=2>"; while(list($keys,$value) = each($staff)){ list($name,$sex,$age) = $value; echo "<tr><td>$name</td><td>$sex</td><td>$age</td></tr>"; } echo "</table>"; ?>
运行结果:
姓名 | 性别 | 年龄 |
小张 | 男 | 24 |
小王 | 女 | 25 |
小李 | 男 | 23 |
<?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
PHP 正则表达式之正则处理函数小结(preg_match,preg_match_all,preg_replace,preg_split)
PHP正则表达式之定界符和原子介绍
PHP超级全局变量数组小结
PHP中数字检测is_numeric与ctype_digit的区别介绍
php 保留字列表
php FLEA中二叉树数组的遍历输出
php数组相加 array(“a”)+array(“b”)结果还是array(“a”)
PHP中数组合并的两种方法及区别介绍
PHP合并两个数组的两种方式的异同
PHP系列学习之日期函数使用介绍
php学习之function的用法
PHP5权威编程阅读学习笔记 附电子书下载
PHP函数学习之PHP函数点评
php array的学习笔记
php统计文件大小,以GB、MB、KB、B输出
PHP数组的交集array_intersect(),array_intersect_assoc(),array_inter_key()函数的小问题
php连接数据库代码应用分析
PHP文件上传原理简单分析
php修改时间格式的代码
PHP第一季视频教程(李炎恢+php100 不断更新)
php学习之变量的使用
php学习之数据类型之间的转换代码
php fputcsv命令 写csv文件遇到的小问题(多维数组连接符)
PHP无限分类代码,支持数组格式化、直接输出菜单两种方式
php简单对象与数组的转换函数代码(php多层数组和对象的转换)
php 数组的一个悲剧?
PHP新手入门学习方法
PHP学习之数组值的操作
PHP学习之数组的定义和填充