Definition and Usage
The uniqid() function generates a unique ID based on the microtime (current time in microseconds).
Note: The generated ID from this function is not optimal, because it is based on the system time. To generate an extremely difficult to predict ID, use the md5() function.
Syntax
uniqid(prefix,more_entropy)
| Parameter | Description |
|---|---|
| prefix | Optional. Specifies a prefix to the unique ID (useful if two scripts generate ids at exactly the same microsecond) |
| more_entropy | Optional. Specifies more entropy at the end of the return value. This will make the result more unique. When set to TRUE, the return string will be 23 characters. Default is FALSE, and the return string will be 13 characters long |
Technical Details
| Return Value: | Returns the unique identifier, as a string |
|---|---|
| PHP Version: | 4+ |
| Changelog: | The prefix parameter became optional in PHP 5.0. The limit of 114 characters long for prefix was raised in PHP 4.3.1. |
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