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StringEndsQ

Status: Stable

documented, exercised by the test suite and/or worked examples, with no known limitations recorded.

Description

StringEndsQ["string", patt]

Gives True if a suffix of "string" matches the string expression patt, and False otherwise.

StringEndsQ["string", {p1, p2, ...}]

Gives True if a suffix matches any of the pi.

StringEndsQ[{s1, s2, ...}, patt]

Gives the list of results for each of the si.

StringEndsQ[patt]

Represents an operator form that can be applied to a string. Equivalent to StringContainsQ["string", patt ~~ EndOfString]. Options: IgnoreCase -> True treats upper/lowercase as equivalent.

Examples (7)

Every input below was run against the current Mathilda build and its output recorded.

Basic examples (4)

In[1]:= StringEndsQ["commit", "it"]
Out[1]= True

In[2]:= StringEndsQ["commit", "mi"]
Out[2]= False

In[3]:= StringEndsQ[{"apple", "banana"}, "a"]
Out[3]= {False, True}

In[4]:= StringEndsQ["a123", DigitCharacter ..]
Out[4]= True

Applications (3)

A matching suffix

In[5]:= StringEndsQ["report.pdf", ".pdf"]
Out[5]= True

No match

In[6]:= StringEndsQ["report.txt", ".pdf"]
Out[6]= False

Threads over a list

In[7]:= StringEndsQ[{"a.c", "b.h", "d.c"}, ".c"]
Out[7]= {True, False, True}

Implementation notes

Algorithm. StringEndsQ is the SQ_ENDS face of the shared sq_dispatch core ā€” the mirror of StringStartsQ. It wraps the pattern as StringExpression[patt, EndOfString], where the translator renders EndOfString as \z (an absolute end anchor), and hands that unanchored to the shared rule builder before the shared sq_match early-exits on the first hit.

Data structures. The synthesised wrapper Expr (outliving the rule set, as RegexRule.lhs borrows into it) and the RegexRule array, whole-match pair only.

Complexity / limits. Equivalent to StringContainsQ[s, patt ~~ EndOfString]. IgnoreCase option; curried operator form StringEndsQ[patt]. A non-string subject leaves the call unevaluated; byte semantics.

Attributes: Protected.

References

Notes & additional examples

Notes

StringEndsQ[s, patt] is equivalent to StringContainsQ[s, patt ~~ EndOfString]: it anchors the pattern to the end of the string by wrapping it as StringExpression[patt, EndOfString] before matching.

It shares the predicate core with StringContainsQ, StringFreeQ, and StringStartsQ, takes an IgnoreCase option, and offers the curried operator form StringEndsQ[patt].