foreach用法

注: foreach 不支持用“@”来禁止错误信息的能力。 <br />
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你可能注意到了以下的代码功能完全相同： <br />
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<?php<br />
$arr = array("one", "two", "three");<br />
reset ($arr);<br />
while (list(, $value) = each ($arr)) {<br />
echo "Value: $value<br>
";<br />
}<br />
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foreach ($arr as $value) {<br />
echo "Value: $value<br>
";<br />
}<br />
?> <br />
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以下代码功能也完全相同： <br />
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<?php<br />
reset ($arr);<br />
while (list($key, $value) = each ($arr)) {<br />
echo "Key: $key; Value: $value<br>
";<br />
}<br />
<br />
foreach ($arr as $key => $value) {<br />
echo "Key: $key; Value: $value<br>
";<br />
}<br />
?> <br />
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示范用法的更多例子： <br />
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<?php<br />
/* foreach example 1: value only */<br />
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$a = array (1, 2, 3, 17);<br />
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foreach ($a as $v) {<br />
print "Current value of $a: $v.
";<br />
}<br />
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/* foreach example 2: value (with key printed for illustration) */<br />
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$a = array (1, 2, 3, 17);<br />
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$i = 0; /* for illustrative purposes only */<br />
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foreach ($a as $v) {<br />
print "$a[$i] => $v.
";<br />
$i++;<br />
}<br />
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/* foreach example 3: key and value */<br />
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$a = array (<br />
"one" => 1,<br />
"two" => 2,<br />
"three" => 3,<br />
"seventeen" => 17<br />
);<br />
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foreach ($a as $k => $v) {<br />
print "$a[$k] => $v.
";<br />
}<br />
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/* foreach example 4: multi-dimensional arrays */<br />
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$a[0][0] = "a";<br />
$a[0][1] = "b";<br />
$a[1][0] = "y";<br />
$a[1][1] = "z";<br />
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foreach ($a as $v1) {<br />
foreach ($v1 as $v2) {<br />
print "$v2
";<br />
}<br />
}<br />
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/* foreach example 5: dynamic arrays */<br />
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foreach (array(1, 2, 3, 4, 5) as $v) {<br />
print "$v
";<br />
}<br />
?>