erase

Delete substrings within strings

Syntax

newStr = erase(str,match)

Description

newStr = erase(str,match) deletes all occurrences of match in str. The erase function returns the remaining text as newStr.

If match is an array, then erase deletes every occurrence of every element of match in str. The str and match arguments do not need to be the same size.

Examples

Delete Substrings from String Array

Create a string array and delete substrings from it. Starting in R2017a, you can create strings using double quotes.

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

str = 2x1 string
    "the quick brown fox jumps"
    "over the lazy dog"

If you are using R2016b, create string arrays using the string function instead of double quotes.

Delete the substring "the " from str. The erase function deletes both instances.

newStr = erase(str,"the ")

newStr = 2x1 string
    "quick brown fox jumps"
    "over lazy dog"

Delete multiple substrings from str.

match = ["the ","quick ","lazy "];
newStr = erase(str,match)

newStr = 2x1 string
    "brown fox jumps"
    "over dog"

Delete File Paths Using Pattern

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 = 3x1 string
    "C:\Temp\MyReport.docx"
    "C:\Data\Experiment1\Trial1\Sample1.csv"
    "C:\Temp\Slides.pptx"

Delete the paths, leaving only file names. To match paths, create a pattern using the wildcardPattern function that matches all text that includes a final "\" character. Use that pattern with the erase function.

match = wildcardPattern + "\"

match = pattern
  Matching:

    wildcardPattern + "\"

filenames = erase(str,match)

filenames = 3x1 string
    "MyReport.docx"
    "Sample1.csv"
    "Slides.pptx"

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

Delete Substring from Character Vector

Create a character vector. Delete the substring, ' World', including the space character.

chr = 'Hello World'

chr = 
'Hello World'

newChr = erase(chr,' World')

newChr = 
'Hello'

Input Arguments

str — Input text

string array | character vector | cell array of character vectors

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

match — Text to delete

string array | character vector | cell array of character vectors | pattern array (since R2020b)

Text to delete, specified as one of the following:

• String array

• Character vector

• Cell array of character vectors

• pattern array (since R2020b)

Tips

• To delete multiple occurrences of a match when the occurrences overlap, use the strrep function. erase only deletes the first occurrence when occurrences overlap.

Extended Capabilities

Tall Arrays

Calculate with arrays that have more rows than fit in memory.

Usage notes and limitations:

• Pattern objects are not supported.

For more information, see Tall Arrays.

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

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

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

Distributed Arrays

Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.

Usage notes and limitations:

• match must be a string array, character vector, or a cell array of character vectors.

For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).