Seperate numbers and Letters & Rearrange the String: Variable Letters Has an Incorrect Value

Write the function Separator that:

Input: inString -- random string scalar mixed with numbers & letters

Tasks:

(1) Seperate Numbers & Letters

(2) Calculate Sum of Numbers

(3) Count Number of Letters (the white spaces counted)

Output:

(1) numbers, string scalar of all numbers in inString with same order.

(2) letters, string scalar of all letters in inString with same order, and white spaces Does Not removed.

(3) sumofNumbers, double precision scalar of sum of all numbers in inString.

(4) numberofLetters, double precision scalar to count all letters in inString, white spaces counted.

Expected Result:

inString: "eng12in13e143e553rin154g 6p547ro548bl645em 8s65ol9v56ing"

numbers: "12131435531546547548645865956"

letters: "engineering problem solving"

sumofNumbers: 131

numberofLetters: 27

Here's My Code:

function [numbers, letters, sumofNumbers, numberofLetters]=Separator(inString)
%Insert your code here
   indexNum = regexp(char(inString), '[0-9]')
   numbers = []
   for i = 1:numel(indexNum)
       numbers = [numbers , inString{1}(indexNum(i))]
   end 
   % numbers 
   numbers = string(numbers)
   % sumofNumbers
   sumofNumbers = 0
   for i = 1:numel(indexNum)
       sumofNumbers = sumofNumbers + str2num(numbers{1}(i))
   end 
   
   words = split(inString)
   letters = []
   count = 0
   for i = 1:numel(words)
        indexLett = regexp(char(words(i)), '[a-z]')
        count = count + numel(indexLett)
        for j = 1:numel(indexLett)
            letters = [letters, words{i}(indexLett(j))]
        end
        letters = strcat(string(letters), " ")
        letters = char(letters)
   end
   % letters
   letters = strip(string(letters))
   comb = split(letters)
   letters = join(comb)
   % number of Literal Letters
   numofTrueLetters = count
   
   % numberofLetters
   numberofLetters = 0
   numberofLetters = strlength(letters)
end 

The Code Returns Exactly As the Expected:

numbers = 

    "12131435531546547548645865956"


letters = 

    "engineering problem solving"


sumofNumbers =

   131


numberofLetters =

    27

However, the MATLAB Grader gives this Answer: "Variable Letters Has an Incorrect Value" and I was confused.

I would be very appreciated if someone could point out the mistake or the error, thank you!

[Cris LaPierre]

This appears to be a function-type problem, so it is likely your function is being tested with other strings as well. Perhaps it is not passing one of those tests? Do you know what input is causing the assessment test to fail? What feedback is showing for the failed test?

For example, what are the expected outputs if inString contains only numbers? Only letters?

[William Wang]

@Cris LaPierre I agree with that there might be other alternative string using for the test, but the matlab grader does not show the details of the input it used.

I tried two string -- "123 456 789" and it returns: numbers is still like this string, and sum is 45 which is correct, and letters & number of letters just return 0*0 scalar.

-- " abc eed efv efw" and it returns the count of 15 with this string, and numbers & sum are 0*0 scalar.

I think the white spaces between my letters might not be exact same as the expected value?

But I split them firstly and join them to ensure that the white spaces are constructed by function, so I think I might try more inputs.

[William Wang]

@Cris LaPierre Alright I got this!

I modified this line, before "[a-z]" and now is "[A-Za-z]" which checks all upper and lower cases for case-insensitivity.

indexLett = regexp(char(words(i)), '[A-Za-z]')

By this way, the indexLett would record all the indexes in the string that has alphabetic letters regardless of case-sensitive, so for more inputs like "Apple is good for health" or "A42pp3113le31 is 31g11oo456d fo442r h105ea422l44t2h" could be counted as the capitalized words in the string.

[Stephen23]

"I think the white spaces between my letters might not be exact same as the expected value? "

That is certainly possible: if the test data includes other types of whitespace characters, then your code will not handle that correctly, e.g. tabs, non-breaking spaces, etc. The assignment specifically states "white spaces Does Not removed." but in your code you remove all of the whitespaces and replace them with space characters, i.e. char(32).

[William Wang]

@Stephen Thank you for this reminding! I just look up the various types of whitespaces, and these could really conduct the different outputs. Understand now!