Create a character vector and replace a substring within it.

chr = 'The quick brown fox'

chr = 
'The quick brown fox'

newChr = strrep(chr,'quick','sly')

newChr = 
'The sly brown fox'

Create a string array. Starting in R2017a, you can create strings using double quotes.

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

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

Replace a substring in each element of the array.

newStr = strrep(str,'the','a')

newStr = 2x1 string
    "a quick brown fox"
    "and a lazy dog"

Replace placeholder content in a cell array, '___', with different values in a second cell array.

C1 = {'Date Received: ___';
      'Date Accepted: ___'};
old = '___';
new = {'2016-09-06';
       '2016-10-11'};
C2 = strrep(C1,old,new)

C2 = 2x1 cell
    {'Date Received: 2016-09-06'}
    {'Date Accepted: 2016-10-11'}

Create a character vector with a repeated, overlapping pattern. Compare the results of using the strrep, replace, and regexprep functions to replace the pattern.

repeats = 'abc 2 def 22 ghi 222 jkl 2222'

repeats = 
'abc 2 def 22 ghi 222 jkl 2222'

Find the indices of the repeating pattern '22' using the strfind function. strfind finds all instances of the pattern, including instances that overlap.

indices = strfind(repeats, '22')

indices = 1×6

    11    18    19    26    27    28

Replace '22' using strrep. When you use strrep, it replaces every instance identified by strfind.

using_strrep = strrep(repeats, '22', '*')

using_strrep = 
'abc 2 def * ghi ** jkl ***'

Replace '22' using replace. It does not replace every instance that strrep replaces.

using_replace = replace(repeats, '22', '*')

using_replace = 
'abc 2 def * ghi *2 jkl **'

Replace '22' using regexprep. The results are identical to the results using the replace function.

using_regexprep = regexprep(repeats, '22', '*')

using_regexprep = 
'abc 2 def * ghi *2 jkl **'

strrep finds all instances of a pattern before replacing any instance. However, the replace and regexprep functions replace an instance of a pattern as soon as they find it within the text.