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StringPosition

gives a list of the starting and ending character positions at which

appears as a substring of

.

gives all positions at which substrings matching the general string expression patt appear in

.

includes only the first n occurrences of patt.

gives positions of all the

.

gives the list of results for each of the

.

MORE INFORMATION

The string expression patt can contain any of the objects specified in the notes for StringExpression.

With the default option setting Overlaps->True, StringPosition includes substrings that overlap. With the setting Overlaps->False, such substrings are excluded. »

With Overlaps->All, multiple substrings that match the same string expression are all included. With Overlaps->True, only the first such matching substring at a given position is included. »

Setting the option IgnoreCase->True makes StringPosition treat lowercase and uppercase letters as equivalent. »

StringPosition returns sequence specifications in the form used by StringTake, StringDrop, and StringReplacePart. »

StringPosition["string", RegularExpression["regex"]] gives positions of substrings matching the specified regular expression.

Basic Examples (2)

Find the starting and ending positions at which "XYZ" occurs in a string:

Find where any pairs of identical characters occur:

Find the starting and ending positions at which "XYZ" occurs in a string:

Out[1]=

Find where any pairs of identical characters occur:

Out[1]=

StringPosition gives substring positions in the form used by functions like StringTake:

Find the position of the first occurrence of "XYZ":

StringPosition by default includes overlaps:

Use Overlaps->False to exclude overlaps:

Treat "a" and "A" as the same:

Treat "a" and "A" as different:

Find successive identical characters independent of case:

StringPosition by default includes overlaps:

By default, StringPosition only includes one substring starting at any given position:

With Overlaps->All, it includes all substrings:

Applications (2)

Find positions of pairs of identical letters in a concatenation sequence:

Find an analogous curve for triples:

Find the positions of the word "president" in the U.S. Constitution:

Properties & Relations (2)

Use StringTake to extract substrings found by StringPosition:

StringCases by default excludes overlaps:

Use StringReplacePart to replace at positions found by StringPosition:

Possible Issues (1)

Lists of string patterns in StringPosition are sometimes not the same as pattern alternatives:

Position StringCases StringCount Characters FindList ReplaceList StringExpression RegularExpression StringDrop StringInsert StringTake SequenceAlignment

Operations on Strings

Special Characters

String Patterns

Working with String Patterns

String Manipulation

String Operations

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