PHP 遍历数组语句总结(foreach,for,list,each)

发布时间：2020-12-13 20:30:10 所属栏目：PHP教程来源：网络整理

导读：在php中遍历循环读出数组的方法有几种，foreach,for,list,each,while都是可以的，只是那种更适合用来遍历数组了。 foreach来访问,遍历的顺序是固定的么? 以什么顺序遍历呢? 比如:代码如下: ?php $colors = array ( red , blue , green , yellow ); foreach (

在php中遍历循环读出数组的方法有几种，foreach,for,list,each,while都是可以的，只是那种更适合用来遍历数组了。

foreach来访问,遍历的顺序是固定的么? 以什么顺序遍历呢?

比如:代码如下:

<?php
$colors= array('red','blue','green','yellow');
foreach ($colors as $color){
//add your codes
}
?>

例2,代码如下:

$capitals= array("Ohio"=> "Columbus","Towa"=> "Des Moines","Arizona"=> "Phoenix");
foreach($capitals as $key=> $val){
//add your codes
}

while()

while() 通常和 list(),each()配合使用,实例代码如下:

<?php
$colors = array('red','yellow');
while(list($key,$val) = each($colors)) {
echo "Other list of $val. ";
}
?>
/*
显示结果：
Other list of red.
Other list of blue.
Other list of green.
Other list of yellow.
*/

3. for(),实例代码如下:

<?php
$arr = array ("0" => "zero","1" => "one","2" => "two");
for ($i = 0;$i < count($arr); $i++) {
$str = $arr[$i];
echo "the number is $str. ";
}
?>
/*
显示结果：
the number is zero.
the number is one.
the number is two.
*/

以下是函数介绍:

key()

mixed key(array input_array)

key()函数返回input_array中位于当前指针位置的键元素。

实例代码如下:

<?php
$capitals = array("Ohio" => "Columbus","Towa" => "Des Moines","Arizona" => "Phoenix");
echo "Can you name the capitals of these states?";
while($key = key($capitals)) {
echo $key." ";
next($capitals);
//每个key()调用不会推进指针。为此要使用next()函数
}
?>
/*结果如下
Can you name the capitals of these states?
Ohio
Towa
Arizona
*/

each() 函数遍历数组

例子1,代码如下:

<?php
$people = array("Peter", "Joe", "Glenn", "Cleveland");
print_r (each($people));
?>
//输出：
//Array ( [1] => Peter [value] => Peter [0] => 0 [key] => 0 )

例子2,代码如下:

each() 经常和 list() 结合使用来遍历数组,本例与上例类似,不过循环输出了整个数组, "Cleveland");

reset($people);

while (list($key, $val) = each($people))

{

echo "$key => $val ";

}

输出：

0 => Peter

1 => Joe

2 => Glenn

3 => Cleveland

多维数组的递归遍历,代码如下:

<?php
/*
* -------------------------------------------------
* Author :
* Url : www.phpfensi.com* Date : 2011-03-09
* -------------------------------------------------
*/
function arr_foreach ($arr)
{
if (!is_array ($arr))
{
return false;
}
foreach ($arr as $key => $val )
{
if (is_array ($val))
{
arr_foreach ($val);
}
else
{
echo $val.' ';
}
}
}
$arr1 = array (1=>array(11,12,13,14=>array(141,142)),2,3,4,5);
echo '<pre>';
print_r($arr1);
echo '<pre>';
arr_foreach ($arr1);
?>
/*
结果
Array
(
[1] => Array
(
[0] => 11
[1] => 12
[2] => 13
[14] => Array
(
[0] => 141
[1] => 142
)
)
[2] => 2
[3] => 3
[4] => 4
[5] => 5
)
11
12
13
141
142
2
3
4
5
*/

（编辑：李大同）

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