---
name: shift
status: documented
runtime: pp
source: src/runtime/pp/aggregate.rs
---
```{index} single: shift; Perl built-in (pp runtime)
```

# shift

## Synopsis

```perl
my $val = shift @array;
my $arg = shift;          # shifts from @_ inside a sub, @ARGV at top level
```

## Description

Removes and returns the first element of an array, shifting all
remaining elements down by one index.

Removes the first element from the array, shifts all remaining
elements down by one, and returns the removed element. Returns
`undef` if the array is empty.

When the SPECIAL flag is set (bare `shift` without an explicit array),
the implicit target depends on call context: inside a subroutine it
reads from `@_` (pad slot 0); at file scope it reads from `@ARGV`.
Handles both regular `Av` and `AliasedAv` (the typical representation
of `@_`).

## See also

unshift, pop, push, splice