extractAfter - Extract substrings after specified positions - MATLAB (original) (raw)

Extract substrings after specified positions

Syntax

Description

[newStr](#bvdoi7q-1-newStr) = extractAfter([str](#bvdoi7q-1%5Fsep%5Fbu4l86d-str),[pat](#bvdoi7q-1-startStr)) extracts the substring that begins after the substring specified bypat and ends with the last character ofstr. If pat occurs multiple times instr, then newStr is str from the first occurrence of pat to the end.

If str is a string array or a cell array of character vectors, then extractAfter extracts substrings from each element ofstr. The output argument newStr has the same data type as str.

example

[newStr](#bvdoi7q-1-newStr) = extractAfter([str](#bvdoi7q-1%5Fsep%5Fbu4l86d-str),[pos](#bvdoi7q-1-startPos)) extracts the substring that begins after the position specified bypos and ends with the last character ofstr.

example

Examples

collapse all

Create string arrays and select text that occurs after substrings.

str = "The quick brown fox"

Extract the substring that occurs after the substring "quick ". The extractAfter function selects the new text but does not include "quick " in the output.

newStr = extractAfter(str,"quick ")

Create a new string array from the elements of a string array. When you specify different substrings as positions, they must be contained in a string array or a cell array that is the same size as the input string array.

str = ["The quick brown fox jumps";"over the lazy dog"]

str = 2×1 string "The quick brown fox jumps" "over the lazy dog"

newStr = extractAfter(str,["quick ";"the "])

newStr = 2×1 string "brown fox jumps" "lazy dog"

You also can specify one substring as a position that is applied to all elements of the input string array.

Since R2020b

Create a string array of file names, including full paths.

str = ["C:\Temp\MyReport.docx"; "C:\Data\Experiment1\Trial1\Sample1.csv"; "C:\Temp\Slides.pptx"]

str = 3×1 string "C:\Temp\MyReport.docx" "C:\Data\Experiment1\Trial1\Sample1.csv" "C:\Temp\Slides.pptx"

To extract the file names, first create a pattern that matches a full path, and then extract what comes after that pattern.

A full path can have several levels, each consisting of any text followed by a "\" character. So start by creating a pattern that matches one level.

level = wildcardPattern + ""

level = pattern Matching:

wildcardPattern + "\"

Then, create a pattern that matches a full path, containing any number of levels.

pat = asManyOfPattern(level)

pat = pattern Matching:

asManyOfPattern(wildcardPattern + "\")

Finally, call extractAfter.

filenames = extractAfter(str,pat)

filenames = 3×1 string "MyReport.docx" "Sample1.csv" "Slides.pptx"

For a list of functions that create pattern objects, see pattern.

Create strings after specified positions.

Select the substring after the 12th character.

newStr = extractAfter(str,12)

Select substrings from each element of a string array. When you specify different positions with numeric arrays, they must be the same size as the input string array.

str = ["Edgar Allen Poe";"Louisa May Alcott"]

str = 2×1 string "Edgar Allen Poe" "Louisa May Alcott"

newStr = extractAfter(str,[12;11])

newStr = 2×1 string "Poe" "Alcott"

Select substrings from each element and specify the same position.

newStr = extractAfter(str,6)

newStr = 2×1 string "Allen Poe" " May Alcott"

Create a character vector. Then create new character vectors that are substrings of chr.

chr = 'peppers and onions'

Select text after the 12th position.

newChr = extractAfter(chr,12)

Select text after a substring.

newChr = extractAfter(chr,'and ')

Input Arguments

collapse all

Input text, specified as a string array, character vector, or cell array of character vectors.

Text or pattern in str that marks the start position for extracted text, specified as one of the following:

String array
Character vector
Cell array of character vectors
pattern array (since R2020b)

The extractAfter function excludespat from the substring that is extracted.

If str is a string array or cell array of character vectors, then you can extract substrings from every element ofstr. You can specify that the substrings either all have the same start or have different starts in each element ofstr.

To specify the same start, specify pat as a character vector, string scalar, or pattern object.
To specify different starts, specify pat as a string array, cell array of character vectors, orpattern array.

Start position, specified as a numeric array.extractAfter excludes the character atpos from the extracted substring.

If str is a string array or cell array of character vectors, then pos can be a numeric scalar or numeric array of the same size as str.

Output Arguments

collapse all

Output text, returned as a string array, character vector, or cell array of character vectors.

Extended Capabilities

expand all

TheextractAfter function supports tall arrays with the following usage notes and limitations:

If pat is an array of pattern objects, the size of the first dimension of the array must be 1.

For more information, see Tall Arrays.

Usage notes and limitations:

str and pat must be a string scalar, a character vector, or a cell array containing not more than one character vector.

Version History

Introduced in R2016b