selection.slice(startOffset[, endOffset]) → selection stream.slice(startOffset[, endOffset]) → stream array.slice(startOffset[, endOffset]) → array binary.slice(startOffset[, endOffset]) → binary string.slice(startOffset[, endOffset]) → string
Return the elements of a sequence within the specified range.
slice
returns the range between startOffset
and endOffset
. If only startOffset
is specified, slice
returns the range from that index to the end of the sequence. Use the optArgs left_bound
or right_bound
as open
or closed
to indicate whether to include that endpoint of the range by default: closed
returns that endpoint, while open
does not. By default, left_bound
is closed and right_bound
is open, so the range (10,13)
will return the tenth, eleventh and twelfth elements in the sequence.
If endOffset
is past the end of the sequence, all elements from startOffset
to the end of the sequence will be returned. If startOffset
is past the end of the sequence or endOffset
is less than startOffset
, a zero-element sequence will be returned.
Negative startOffset
and endOffset
values are allowed with arrays; in that case, the returned range counts back from the array’s end. That is, the range (-2)
returns the last two elements, and the range of (2,-1)
returns the second element through the next-to-last element of the range. An error will be raised on a negative startOffset
or endOffset
with non-arrays. (An endOffset
of −1 is allowed with a stream if rightBound
is closed; this behaves as if no endOffset
was specified.)
If slice
is used with a binary object, the indexes refer to byte positions within the object. That is, the range (10,20)
will refer to the 10th byte through the 19th byte.
With a string, slice
behaves similarly, with the indexes referring to Unicode codepoints. String indexes start at 0
. (Note that combining codepoints are counted separately.)
Example: Return the fourth, fifth and sixth youngest players. (The youngest player is at index 0, so those are elements 3–5.)
r.table("players").orderBy().optArg("index", "age").slice(3, 6).run(conn);
Example: Return all but the top three players who have a red flag.
r.table("players").filter(r.hashMap("flag", "red")).orderBy() .optArg("index", r.desc("score")).slice(3).run(conn);
Example: Return holders of tickets X
through Y
, assuming tickets are numbered sequentially. We want to include ticket Y
.
r.table("users").orderBy().optArg("index", "ticket") .slice(x, y).optArg("right_bound", "closed").run(conn);
Example: Return the elements of an array from the second through two from the end (that is, not including the last two).
r.expr(r.array(0, 1, 2, 3, 4, 5)).slice(2, -2).run(conn);
Result:
[2,3]
Example: Return the third through fifth characters of a string.
r.expr("rutabaga").slice(2,5).run(conn);
Result:
"tab"
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https://rethinkdb.com/api/java/slice/