Slice
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slice
returns a subset of a string or list. This is equivalent to using the square-brackets slice operator seq[from:to]
, but with ordinary
function syntax.
Arguments
Parameter Name | Type | Meaning |
---|---|---|
seq | string or list | sequence to get a subsequence of |
from | number, default | 0-based index to the first element to return (if negative, counts from the end) |
to | number, optional | 0-based index of first element to *not* include in the result (if negative, count from the end; if omitted, return the rest of the sequence) |
Usage Notes
The from and to indexes are automatically limited to the range of the sequence; they never cause an Index Error. This provides for a useful idiom: to get element i of a sequence, or an empty value if sequence is too short to have such an element, use seq[i:i+1]
. This differs from seq[i]
in that the latter will result in an Index Error if i is out of range.
Example
slice("Hello", -2) // returns "lo"
"Hello"[-2:] // equivalent to the above
slice("x", -2) // returns "x"
"x"[-2:] // equivalent to the above
slice([10,20,30,40,50], 1, 3) // returns [20, 30]
[10,20,30,40,50][1:3] // equivalent to the above