PHP array_unshift () function
Examples
Insert Element "blue" to the array:
<?php
$a=array("a"=>"red","b"=>"green");
array_unshift($a,"blue");
print_r($a);
?>
$a=array("a"=>"red","b"=>"green");
array_unshift($a,"blue");
print_r($a);
?>
Running instance »
Definition and Usage
array_unshift () function is used to insert new elements in the array. Value of the new array will be inserted at the beginning of the array.
Tip: You can insert one or more values.
Note: The key name value from 0 to 1 increments.String keys will remain unchanged.
grammar
array_unshift( array,value1,value2,value3... )
| 参数 | 描述 |
|---|---|
| array | 必需。规定数组。 |
| value1 | 必需。规定插入的值。 |
| value2 | 可选。规定插入的值。 |
| value3 | 可选。规定插入的值。 |
technical details
| return value: | Returns the number of new elements in the array. |
|---|---|
| PHP version: | 4+ |
More examples
Example 1
Show the return value:
<?php
$a=array("a"=>"red","b"=>"green");
print_r(array_unshift($a,"blue"));
?>
$a=array("a"=>"red","b"=>"green");
print_r(array_unshift($a,"blue"));
?>
Running instance »
Example 2
Using numeric keys:
<?php
$a=array(0=>"red",1=>"green");
array_unshift($a,"blue");
print_r($a);
?>
$a=array(0=>"red",1=>"green");
array_unshift($a,"blue");
print_r($a);
?>
Running instance »
Complete PHP Array Reference