in_array() definition and usage_PHP tutorial

A basic tutorial for getting started with PHP. Friends in need can refer to it on how to use the in_array function.

bool in_array ( mixed $needle , array $haystack [, bool $strict ] )
Searches the haystack for needle and returns TRUE if found, FALSE otherwise.

If the value of the third parameter strict is TRUE, the in_array() function will also check whether the type of needle is the same as that in haystack.

Note:

If needle is a string, the comparison is case-sensitive.

Note:

Prior to PHP version 4.2.0, needle was not allowed to be an array.

Note: If the value parameter is a string and the type parameter is set to true, the search is case-sensitive.

Example #1 in_array() Example

The code is as follows

代码如下	复制代码
$os = array("Mac", "NT", "Irix", "Linux"); if (in_array("Irix", $os)) {     echo "Got Irix"; } if (in_array("mac", $os)) {     echo "Got mac"; } ?>

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$os = array("Mac", "NT", "Irix", "Linux"); if (in_array("Irix", $os)) {

echo "Got Irix";
}

if (in_array("mac", $os)) {

代码如下	复制代码
$a = array('1.10', 12.4, 1.13); if (in_array('12.4', $a, true)) {     echo "'12.4' found with strict checkn"; } if (in_array(1.13, $a, true)) {     echo "1.13 found with strict checkn"; } ?>

echo "Got mac";

}
?>

The second condition fails because in_array() is case sensitive, so the above program reads:

Got Irix


Example #2 in_array() strict type checking example

$a = array('1.10', 12.4, 1.13);

if (in_array('12.4', $a, true)) {

echo "'12.4' found with strict checkn"; } if (in_array(1.13, $a, true)) { echo "1.13 found with strict checkn"; } ?> Note: in_array function returns 0,1

When converted to boolean, the following values ​​are considered FALSE: Boolean value FALSE Integer value 0 (zero)

Floating point value 0.0 (zero)

Blank string and string "0" Array without member variables Object without units Special type NULL (including variables that have not been set) All other values ​​are considered TRUE (including any resources). Warning -1, like other non-zero values ​​(positive or negative), is considered TRUE http://www.bkjia.com/PHPjc/629252.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/629252.htmlTechArticleA basic tutorial for getting started with PHP. Regarding how to use the in_array function, friends in need can refer to it. bool in_array ( mixed $needle , array $haystack [, bool $strict ] ) in h...

The code is as follows	Copy code