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Mathematica > Core Language > String Manipulation > String Operations > StringCount >

StringCount

gives a count of the number of times

appears as a substring of

.

gives the number of substrings in

that match the general string expression patt.

counts the number of occurrences of any of 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->False, overlapping substrings are not treated as separate. With the setting Overlaps->True, StringCount counts substrings that overlap as separate.

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

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

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

Basic Examples (2)

The number of occurrences of

in the string

:

Count the number of substrings of the form

for different x characters:

The number of occurrences of

in the string

:

Out[1]=

Count the number of substrings of the form

for different x characters:

Out[1]=

Use string patterns:

Regular expressions:

Mixed regular expressions and string patterns:

Count occurrences of either substrings:

StringCount automatically threads over lists of strings:

The number of occurrences of

in

:

Ignore case:

All substrings in

starting and ending with

:

StringCount does not include overlaps by default:

This includes the overlaps:

This includes overlaps starting at the same position:

Applications (3)

A 10-million-base random DNA string:

The number of sequences with adenine symmetrically placed:

Find how many words occur in the U.S. Constitution:

The number of occurrences of the word

:

All strings made of two characters with length 4 and which overlap themselves:

Properties & Relations (1)

StringCount gives the number of matching substrings:

The length of matching substrings obtained from StringCases:

Count StringFreeQ StringPosition StringCases Characters StringExpression RegularExpression

Operations on Strings

Special Characters

String Patterns

Working with String Patterns

Linguistic Data

Processing Textual Data

String Manipulation

String Operations

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