extractBefore

Create string arrays and select text that occurs before substrings.

str = "The quick brown fox"

str = 
"The quick brown fox"

Extract the substring that occurs before the substring " brown". The extractBefore function selects the text but does not include " brown" in the output.

newStr = extractBefore(str," brown")

newStr = 
"The 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 str.

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

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

newStr = extractBefore(str,[" brown";" dog"])

newStr = 2x1 string
    "The quick"
    "over the lazy"

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

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"

To extract the paths, first create a pattern that matches the file name at the end of a path, and then extract the path that comes before 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 any characters except the "\" character.

name = wildcardPattern("Except","\")

name = pattern
  Matching:

    wildcardPattern("Except","\")

Then, create a pattern that matches any name found between a "\" character and the end of a string. Use the textBoundary function to match the end of a string.

pat = "\" + name + textBoundary

pat = pattern
  Matching:

    "\" + wildcardPattern("Except","\") + textBoundary

Finally, call extractBefore.

paths = extractBefore(str,pat)

paths = 3x1 string
    "C:\Temp"
    "C:\Data\Experiment1\Trial1"
    "C:\Temp"

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

Create strings before specified positions.

str = "Edgar Allen Poe"

str = 
"Edgar Allen Poe"

Select the substring before the sixth character.

newStr = extractBefore(str,6)

newStr = 
"Edgar"

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 = 2x1 string
    "Edgar Allen Poe"
    "Louisa May Alcott"

newStr = extractBefore(str,[6;7])

newStr = 2x1 string
    "Edgar"
    "Louisa"

Select substrings from each element and specify the same position.

newStr = extractBefore(str,12)

newStr = 2x1 string
    "Edgar Allen"
    "Louisa May "

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

chr = 'peppers and onions'

chr = 
'peppers and onions'

Select the substring before the eighth position.

newChr = extractBefore(chr,8)

newChr = 
'peppers'

Select text before a substring.

newChr = extractBefore(chr,' and')

newChr = 
'peppers'