PHP generates an instance of GUID (globally unique identifier) _php tutorial

GUID: The globally unique Identifier (globally unique identifier) is also known as the UUID (universally unique Identifier). A GUID is a 128-bit numeric identifier produced by a particular algorithm that indicates the uniqueness of the product. GUIDs are primarily used to assign identifiers that must be unique in a network or system that has multiple nodes, multiple computers, and more than one computer.

On the Windows platform, GUIDs are widely used in Microsoft products to identify objects such as registry keys, class and interface identifiers, databases, system catalogs, and so on.

The format of the GUID is "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", where each x is a 32-bit hexadecimal number in the range of 0-9 or a-f. For example, 6F9619FF-8B86-D011-B42D-00C04FC964FF is a valid GUID value.

★guid are unique in space and time, guaranteeing that the numbers produced at different places at the same time are different. ★ No two computers in the world will generate duplicate GUID values. ★ When a GUID is required, it can be generated automatically by the algorithm and does not require an authoritative authority to manage it. The length of the ★guid is fixed and relatively short, and is ideal for sorting, labeling, and storage.

Code:

Copy to ClipboardWhat to refer to: [www.bkjia.com]function Create_guid () {
$charid = Strtoupper (MD5 (Uniqid (Mt_rand (), true));
$hyphen = Chr (45);//"-"
$uuid = Chr (123)//"{"
. substr ($charid, 0, 8). $hyphen
. substr ($charid, 8, 4). $hyphen
. substr ($charid, 4). $hyphen
. substr ($charid, 4). $hyphen
. substr ($charid, 20,12)
. chr (125);//"}"
return $uuid;
}

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