【标题】：php学习笔记7-(数组操作)
【关键字】：php,7-
【来源】：http://blog.csdn.net/yxf/archive/2006/10/05/1322080.aspx

php学习笔记7-(数组操作)

php支持两种数组，一种是普通的数字索引的数组，从0开始，类似Java（为什么不说C呢？因为数组的数组是多维数组，然而子数组的长度可以是任意的，不必每个都相同，php中的数组都是这样的）。还支持另外一种数组，key/value进行映射的数组，相当于java中的Hashtable。数组的操作方式也是多种多样的，这里还提到了foreach的用法。
foreach ( $array as $value ) ...;
foreach ( $array as $key=>$value ) ...;

这次的程序同样是一个解释执行的普通脚本，而非一个服务器脚本。

#!/usr/bin/php

<?php

# array declare

$strs=array('a','b','c');

echo "Stage 1: ";

for ( $i=0; $i<count($strs); $i++ )

echo "$strs[$i] ";

echo " ";

# array_push() / array_pop() <-- operate like a stack

$numbers=array();

echo "Stage 2: ";

for ( $i=0; $i<10; $i++ ) array_push($numbers,$i*3); // append an element

foreach ( $numbers as $x ) echo "$x ";

echo " ";

while ( count($numbers)>0 )

echo array_pop($numbers)." ";

echo " ";

# key / value

echo "Stage 3: ";

$prices=array('Lyre'=>250,'Shaka'=>600,'Sakura'=>20,'Aiakos'=>280);

foreach ( $prices as $key=>$value ) echo "$key : $value ";

echo " ";

# browse an array

echo "Stage 4: ";

reset($prices); # move the pointer to the start of the array

while ( list($product, $price)=each($prices) ) { # here, each() returns the current element as an array

# and assigned to $product and $price by the result of

# list(), then each() moves the pointer to the next element

echo "$product : $price ";

}

# current(), each(), next(), prev(), pos(), reset(), end()

echo "----------------- ";

$value=end($prices); // move to the end of the array

do {

echo $value." "; # pos() 的返回让我很惊讶！

$value=prev($prices);

} while ( $value );

echo " ";

# 多维数组

echo "Stage 5: ";

$multi_way=array( # declare is so simple

array(1,2,3,4,5), # 5 elements

array('this','is','an','array') # 4 elements

);

for ( $i=0; $i<count($multi_way); $i++ ) :

for ( $j=0; $j<count($multi_way[$i]); $j++ ) echo $multi_way[$i][$j].' '; # do not include

# $multi_way[$i][$j] into

# a string

echo " ";

endfor;

echo "------------------ ";

foreach ( $multi_way as $sub_arr ) :

foreach ( $sub_arr as $sub_value ) echo "$sub_value ";

echo " ";

endforeach;

echo " ";

# shuffle() - random an array

# range(start,end[,step]) - generate an array

# array_reverse() - reverse an array

# sort(), usort()(sort according to an user defined function),

# asort()(sort an key/value array), ksort()(only sort the keys)

# rsort(), arsort(), krsort() <== sort by descendant order

echo "Stage 6: ";

$tens=range(1,10,2);