(PHP 4, PHP 5)
in_array — 检查数组中是否存在某个值
在 haystack 中搜索
needle，如果找到则返回 TRUE，否则返回 FALSE。
如果第三个参数 strict 的值为
TRUE 则 in_array() 函数还会检查
needle 的类型是否和
haystack 中的相同。
Note:
如果
needle是字符串，则比较是区分大小写的。
Note:
在 PHP 版本 4.2.0 之前，
needle不允许是一个数组。
Example #1 in_array() 例子
<?php
$os = array("Mac", "NT", "Irix", "Linux");
if (in_array("Irix", $os)) {
echo "Got Irix";
}
if (in_array("mac", $os)) {
echo "Got mac";
}
?>
第二个条件失败，因为 in_array() 是区分大小写的，所以以上程序显示为：
Got Irix
Example #2 in_array() 严格类型检查例子
<?php
$a = array('1.10', 12.4, 1.13);
if (in_array('12.4', $a, true)) {
echo "'12.4' found with strict check\n";
}
if (in_array(1.13, $a, true)) {
echo "1.13 found with strict check\n";
}
?>
以上例程会输出：
1.13 found with strict check
Example #3 in_array() 中用数组作为 needle
<?php
$a = array(array('p', 'h'), array('p', 'r'), 'o');
if (in_array(array('p', 'h'), $a)) {
echo "'ph' was found\n";
}
if (in_array(array('f', 'i'), $a)) {
echo "'fi' was found\n";
}
if (in_array('o', $a)) {
echo "'o' was found\n";
}
?>
以上例程会输出：
'ph' was found 'o' was found
needle
The searched value.
Note:
If
needleis a string, the comparison is done in a case-sensitive manner.
haystack
The array.
strict
If the third parameter strict is set to TRUE
then the in_array() function will also check the
types of the
needle in the haystack.
Returns TRUE if needle is found in the array,
FALSE otherwise.
| 版本 | 说明 |
|---|---|
| 4.2.0 |
needle may now be an array.
|
Example #4 in_array() example
<?php
$os = array("Mac", "NT", "Irix", "Linux");
if (in_array("Irix", $os)) {
echo "Got Irix";
}
if (in_array("mac", $os)) {
echo "Got mac";
}
?>
The second condition fails because in_array() is case-sensitive, so the program above will display:
Got Irix
Example #5 in_array() with strict example
<?php
$a = array('1.10', 12.4, 1.13);
if (in_array('12.4', $a, true)) {
echo "'12.4' found with strict check\n";
}
if (in_array(1.13, $a, true)) {
echo "1.13 found with strict check\n";
}
?>
以上例程会输出：
1.13 found with strict check
Example #6 in_array() with an array as needle
<?php
$a = array(array('p', 'h'), array('p', 'r'), 'o');
if (in_array(array('p', 'h'), $a)) {
echo "'ph' was found\n";
}
if (in_array(array('f', 'i'), $a)) {
echo "'fi' was found\n";
}
if (in_array('o', $a)) {
echo "'o' was found\n";
}
?>
以上例程会输出：
'ph' was found 'o' was found