Fomo3D系统APP开发制作

php 中 foreach() 函数的用法以及 Fomo3D 系统 APP 开发制作源代码介绍 T：/ I8O-2853-296O / 黎灿 +foreach() 有两种用 法：

1：foreach(array_name as $value) {statement;}

 这里的 array_name 是你要遍历的数组名，每次循环中，array_name 数组的当前元素的值被赋给 $value, 并且数组内部的下标向下移一 步，也就是下次循环回得到下一个元素。

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

 这里跟第一种方法的区别就是多了个 $key, 也就是除了把当前元素的值赋给 $value 外，当前元素的键值也会在每次循环中被赋给变量 $key。键值可以 是下标值，也可以是字符串。比如 book[0]= 1 中的“0”，book[id]="001" 中的“id”.

示范用法的更多例子：

<?php
/————————————————————————-/
/ foreach example 1: value only /
echo “foreach example 1: value only “.’
‘;

$a = array(1, 2, 3, 17);

foreach ($a as $v) {
echo “Current value of “$a: $v”.’
‘;
}

/————————————————————————-/
/ foreach example 2: value (with key printed for illustration) /
echo ‘
‘.’
‘.”foreach example 2: value (with key printed for illustration) “.’
‘;

$a = array(1, 2, 3, 17);

$i = 0; / for illustrative purposes only /

foreach ($a as $v) {

echo ""$a[$i] => $v".'<br />';
$i++;

}

/————————————————————————-/
/ foreach example 3: key and value /
echo ‘
‘.’
‘.”foreach example 3: key and value “.’
‘;

$a = array(

"one" => 1,
"two" => 2,
"three" => 3,
"seventeen" => 17

);

foreach ($a as $k => $v) {

echo ""$a[$k] => $v".'<br />';

}

/————————————————————————-/
/ foreach example 4: multi-dimensional arrays /
echo ‘
‘.’
‘.”foreach example 4: multi-dimensional arrays “.’
‘;

$a = array();
$a0 = “a”;
$a0 = “b”;
$a1 = “y”;
$a1 = “z”;

foreach ($a as $v1) {

foreach ($v1 as $v2) {echo "$v2"n";}

}

/————————————————————————-/
/ foreach example 5: dynamic arrays /
echo ‘
‘.’
‘.”foreach example 5: dynamic arrays “.’
‘;

foreach (array(1, 2, 3, 4, 5) as $v) {

echo "$v"n";

}
?>

结果如下:

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

foreach example 2: value (with key printed for illustration)
$a[0] => 1
$a[1] => 2
$a[2] => 3
$a[3] => 17

foreach example 3: key and value
$a[one] => 1
$a[two] => 2
$a[three] => 3
$a[seventeen] => 17

foreach example 4: multi-dimensional arrays
a b y z

foreach example 5: dynamic arrays
1 2 3 4 5

/ foreach example 3: key and value /
echo ‘
‘.’
‘.”foreach example 3: key and value “.’
‘;

$messageNav[‘ 首页 ’] =ROOT_PATH;

$messageNav[‘ 人才交流 ’] =”#”

$messageNav[‘ 动态专栏 ’] =”hragent/cn/”

<?php $i = 0;foreach ($messageNav as $key=>$value):?>

<?php if ($i != count($messageNav) – 1):?>