i;;j
represents a span of elements i through j.
i;;
represents a span from i to the end.
;;j
represents a span from the beginning to j.
;;
represents a span that includes all elements.
i;;j;;k
represents a span from i through j in steps of k.
i;;;;k
represents a span from i to the end in steps of k.
;;j;;k
represents a span from the beginning to j in steps of k.
;;;;k
represents a span from the beginning to the end in steps of k.
Span
i;;j
represents a span of elements i through j.
i;;
represents a span from i to the end.
;;j
represents a span from the beginning to j.
;;
represents a span that includes all elements.
i;;j;;k
represents a span from i through j in steps of k.
i;;;;k
represents a span from i to the end in steps of k.
;;j;;k
represents a span from the beginning to j in steps of k.
;;;;k
represents a span from the beginning to the end in steps of k.
Details
- m[[i;;j;;k]] is equivalent to Take [m,{i,j,k}].
- m[[i;;j]]=v can be used to reset a span of elements in a list or other expression.
- When used in Part , negative i and j count from the end.
- In i;;j, i;;j;;k, etc., i and j can be of the form UpTo [n].
- Any argument of Span […] can be All , in which case it is interpreted as returning the largest possible number of elements consistent with any possible value of that argument.
Examples
open all close allBasic Examples (3)
Take a span of elements from a list:
Take every third element:
Assign to a span of elements:
Assign a sequence of different elements:
Scope (7)
Negative indices count from the end:
A negative step size extracts elements in reverse order:
Take all elements from the third position to the end:
Take the first five characters:
Take every other element:
Use UpTo to restrict the right endpoint of the span to the length of the list:
Use UpTo to restrict the left endpoint of the span to the length of the list:
Properties & Relations (4)
All in the first argument of Span is equivalent to the value 1:
All in the second argument of Span is equivalent to the value -1:
All in the third argument of Span is equivalent to the value 1 or -1:
The value is chosen to given a non-empty range:
When operating on the expression expr, UpTo [n] is equivalent to Min [n,Length [expr]]:
Verify the equivalence:
In this case, only the element b is extracted:
Related Guides
Text
Wolfram Research (2007), Span, Wolfram Language function, https://reference.wolfram.com/language/ref/Span.html (updated 2017).
CMS
Wolfram Language. 2007. "Span." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2017. https://reference.wolfram.com/language/ref/Span.html.
APA
Wolfram Language. (2007). Span. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Span.html
BibTeX
@misc{reference.wolfram_2025_span, author="Wolfram Research", title="{Span}", year="2017", howpublished="\url{https://reference.wolfram.com/language/ref/Span.html}", note=[Accessed: 17-November-2025]}
BibLaTeX
@online{reference.wolfram_2025_span, organization={Wolfram Research}, title={Span}, year={2017}, url={https://reference.wolfram.com/language/ref/Span.html}, note=[Accessed: 17-November-2025]}