PHP 遍历数组语句总结(foreach,for,list,each)
PHP 遍历数组语句总结(foreach,for,list,each)
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
$capitals= array("Ohio"=> "Columbus","Towa"=> "Des Moines","Arizona"=> "Phoenix");
foreach($capitals as $key=> $val){
//add your codes
}
while()
while() 通常和 list()，each()配合使用。
#example2:
代码如下
<?php
$colors = array('red','blue','green','yellow');
while(list($key,$val) = each($colors)) {
echo "Other list of $val.<br />";
}
?>
显示结果：
Other list of red.
Other list of blue.
Other list of green.
Other list of yellow.
3. for()
#example3:
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.<br />";
}
?>
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。
#example4
代码如下
<?php
$capitals = array("Ohio" => "Columbus","Towa" => "Des Moines","Arizona" => "Phoenix");
echo "<p>Can you name the capitals of these states?</p>";
while($key = key($capitals)) {
echo $key."<br />";
next($capitals);
//每个key()调用不会推进指针。为此要使用next()函数
}
?>
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 )
子 2
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：
代码如下
复制代码
<?php
$people = array("Peter", "Joe", "Glenn", "Cleveland");
reset($people);
while (list($key, $val) = each($people))
{
echo "$key => $val<br />";
}
?>
输出：
0 => Peter
1 => Joe
2 => Glenn
3 => Cleveland
多维数组的递归遍历
代码如下
<?php
/*
* -------------------------------------------------
* Author :
* Url : www.45it.com* Date : 2011-03-09
* -------------------------------------------------
*/
function arr_foreach ($arr)
{
if (!is_array ($arr))
{
return false;
}
foreach ($arr as $key => $val )
{
if (is_array ($val))
{
arr_foreach ($val);
}
else
{
echo $val.'<br/>';
}
}
}
$arr1 = array (1=>array(11,12,13,14=>array(141,142)),2,3,4,5);
echo '<pre>';
print_r($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