PHP prev() function
Example
Output the values of the current element, next element, and previous element in the array:
<?php
$people = array("Bill", "Steve", "Mark", "David");
echo current($people) . "<br>";
echo next($people) . "<br>";
echo prev($people);
?>
Definition and usage
The prev() function points the internal pointer to the previous element in the array and outputs.
Related methods:
- next() - Points the internal pointer to the next element in the array and outputs
- current() - Returns the value of the current element in the array
- end() - Points the internal pointer to the last element in the array and outputs
- reset() - Points the internal pointer to the first element in the array and outputs
- each() - Returns the key name and key value of the current element, and moves the internal pointer forward
Syntax
prev(array)
| Parameter | Description |
|---|---|
| array | Required. Specifies the array to use |
Description
The behavior of prev() and next() is similar, but it moves the internal pointer back one position instead of forward one.
Note:If the array contains empty units, or the value of the unit is 0, this function will also return FALSE when it encounters these units. To correctly traverse an array that may contain empty units or units with a value of 0, please refer to the each() function.
Technical details
| Return value: | If successful, it returns the value of the previous element in the array, or FALSE if there are no more array elements. |
| PHP Version: | 4+ |
More Examples
Example 1
Demonstrate all related methods:
<?php
$people = array("Bill", "Steve", "Mark", "David");
echo current($people) . "<br>"; // The current element is Bill
echo next($people) . "<br>"; // Bill's next element is Steve
echo current($people) . "<br>"; // The current element is now Steve
echo prev($people) . "<br>"; // The previous element of Steve is Bill
echo end($people) . "<br>"; // The last element is David
echo prev($people) . "<br>"; // The element before David is Mark
echo current($people) . "<br>"; // The current element is Mark
echo reset($people) . "<br>"; // Moves the internal pointer to the first element of the array, that is, Bill
echo next($people) . "<br>"; // Bill's next element is Steve
print_r (each($people)); // Returns the key name and value of the current element (currently Steve) and moves the internal pointer forward
?>
