php中用foreach來操作數(shù)組的代碼

更新時間：2011年07月17日 01:25:20 作者：

php中用foreach來操作數(shù)組的代碼，需要的朋友可以參考下。

foreach()有兩種用法：

 
foreach(array_name as $value) 
{ 
statement; 
} 

這里的array_name是你要遍歷的數(shù)組名，每次循環(huán)中，array_name數(shù)組的當前元素的值被賦給$value,并且數(shù)組內部的下標向下移一步，也就是下次循環(huán)回得到下一個元素。

復制代碼代碼如下:

 
foreach(array_name as $key => $value) 
{ 
statement; 
} 

這里跟第一種方法的區(qū)別就是多了個$key,也就是除了把當前元素的值賦給$value外，當前元素的鍵值也會在每次循環(huán)中被賦給變量$key。鍵值可以是下標值，也可以是字符串。比如book[0]=1中的"0"，book[id]="001"中的"id".
程序實例1：

復制代碼代碼如下:

 
<?php 
/*-------------------------------------------------------------------------*/ 
/* foreach example 1: value only */ 
echo "foreach example 1: value only ".'<br />'; 
$a = array(1, 2, 3, 17); 
foreach ($a as $v) { 
echo "Current value of ".$a.":". $v."<br />"; 
} 
?> 
// 運行結果 
foreach example 1: value only 
Current value of $a: 1 
Current value of $a: 2 
Current value of $a: 3 
Current value of $a: 17 

2

復制代碼代碼如下:

 
/*-------------------------------------------------------------------------*/ 
/* foreach example 2: value (with key printed for illustration) */ 
echo '<br />'.'<br />'."foreach example 2: value (with key printed for illustration) ".'<br />'; 
$a = array(1, 2, 3, 17); 
$i = 0; /* for illustrative purposes only */ 
foreach ($a as $v) { 
echo ""$a[$i] => $v".'<br />'; 
$i++; 
} 
// 程序運行結果 
foreach example 2: value (with key printed for illustration) 
$a[0] => 1 
$a[1] => 2 
$a[2] => 3 
$a[3] => 17 

3

復制代碼代碼如下:

 
/*-------------------------------------------------------------------------*/ 
/* foreach example 3: key and value */ 
echo '<br />'.'<br />'."foreach example 3: key and value ".'<br />'; 
$a = array( 
"one" => 1, 
"two" => 2, 
"three" => 3, 
"seventeen" => 17 
); 
foreach ($a as $k => $v) { 
echo ""$a[$k] => $v".'<br />'; 
} 
// 程序運行結果 
foreach example 3: key and value 
$a[one] => 1 
$a[two] => 2 
$a[three] => 3 
$a[seventeen] => 17 

4

復制代碼代碼如下:

 
/*-------------------------------------------------------------------------*/ 
/* foreach example 4: multi-dimensional arrays */ 
echo '<br />'.'<br />'."foreach example 4: multi-dimensional arrays ".'<br />'; 
$a = array(); 
$a[0][0] = "a"; 
$a[0][1] = "b"; 
$a[1][0] = "y"; 
$a[1][1] = "z"; 
foreach ($a as $v1) { 
foreach ($v1 as $v2) { 
echo "$v2"n"; 
} 
} 
// 程序運行結果 
foreach example 4: multi-dimensional arrays 
a b y z 

5

復制代碼代碼如下:

 
/*-------------------------------------------------------------------------*/ 
/* foreach example 5: dynamic arrays */ 
echo '<br />'.'<br />'."foreach example 5: dynamic arrays ".'<br />'; 
foreach (array(1, 2, 3, 4, 5) as $v) { 
echo "$v"n"; 
} 
// 程序運行結果 
foreach example 5: dynamic arrays 
1 2 3 4 5 

也可以這么用：

復制代碼代碼如下:

 
$messageNav['首頁'] =ROOT_PATH; 
$messageNav['人才交流'] ="#" 
$messageNav['動態(tài)專欄'] ="hragent/cn/" 
<?php $i = 0;foreach ($messageNav as $key=>$value):?> 
<?php if ($i != count($messageNav) - 1):?> 
<a href="<?=$value?>"><?=$key?></a>> 
<?php else:?> 
<a href="<?=$value?>" class="onlink"><?=$key?></a> 
<?php endif;?> 
<?php $i++;endforeach;?> 

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