array_slice() returns the sequence of elements from the array array as specified by the offset and length parameters.
If offset is positive, the sequence will start at that offset in the array. If offset is negative, the sequence will start that far from the end of the array.
If length is given and is positive, then the sequence will have that many elements in it. If length is given and is negative then the sequence will stop that many elements from the end of the array. If it is omitted, then the sequence will have everything from offset up until the end of the array.
Note that array_slice() will ignore array keys, and will calculate offsets and lengths based on the actual positions of elements within the array.
See also array_splice() and unset().