strcat including space (i.e, ' ')

I have to concatenate words, including spaces

Ex. a='word1'; b='word2';c=strcat(a,' ',b);

I need 'word1 word2', however, the value on c is 'word1word2'

Can you help me?

Answer 1

[Walter Roberson]

To include spaces when concatenating character vectors, use square brackets.

a = 'word1';
b = 'word2';
c = [a ' ' b]

The “ strcat ” function ignores trailing whitespace characters in character vectors. However, “strcat” preserves them in cell arrays of character vectors or string arrays.

a = {'word1'};
b = {'word2'};
c = strcat(a,{' '},b)

You also can use the “plus” operator to combine strings. Starting in R2017a, use double quotes to create strings. For more information on strings, see the “ string ” data type.

a = "word1";
b = "word2";
c = a + " " + b

[Paulo Silva]

Walter I'm sorry but this time I have to disagree with your answer, you said strcat({'word1'},{' '},{'word2'}) but that doesn't work properly for the question and example, that's working with cells (input and output) and the user just wants strings.

[Walter Roberson]

So? The user also wanted variables instead of constants. I illustrated the principle and the user can adapt from there, such as using

c = char(strcat(a,{' '},b));

[Jan]

@CELL/STRCAT is a not efficiently implemented M-function. It is easy to improve it and remove the strange deleting of marinal spaces. This behaviour is kept from the Matlab 4 times, before CELL-strings allowed to create a container for strings of different lengths.

[Paulo Silva]

variables, constants, strings and cells

Too many assumptions for such small question but it's all ok

Answer 2

[Paulo Silva]

c=[a ' ' b]

strcat ignores trailing ASCII white space characters and omits all such characters from the output. White space characters in ASCII are space, newline, carriage return, tab, vertical tab, or form-feed characters, all of which return a true response from the MATLAB isspace function. Use the concatenation syntax [s1 s2 s3 ...] to preserve trailing spaces. strcat does not ignore inputs that are cell arrays of strings.

Reference

[Daniel Foose]

This is better than the accepted answer because it keeps the type the same. The accepted answer returns a cell with a string in it (which is different from a string). This answer returns a string.

[Walter Roberson]

The accepted answer returns a cell with a character vector in it. Strings did not exist in R2011a. If strings were being used then you would use a different approach:

>> a = "word1"; b = "word2"; a + " "  + b
ans = 
    "word1 word2"

This requires R2017a or later. For R2016b,

>> a = string('word1'); b = string('word2'); a + ' ' + b

and before R2016b strings did not exist.

Answer 3

[Usman Nawaz]

use double quotes instead of single quotes, worked for me.

[Walter Roberson]

That can be useful, but the output would be a string() object instead of a character vector. string() objects can be useful, but they need slightly different handling than character vectors.

string() objects became available in R2016b; using double-quotes to indicate string objects became available in R2017a.

Answer 4

[R P]

Thank you, Walter

[Paulo Silva]

Please always test the answers provided before accepting them, Walter answer isn't correct (this time).

[Walter Roberson]

>> strcat({'word1'},{' '},{'word2'})

ans =

'word1 word2'

You can dereference this or cell2mat it if you want the string itself as output.

[Jan]

@Walter: CELL2MAT is not efficient here. S{1} is nicer.