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The program takes a numbers only input

If the users enters a letter /alphabets it gets caught and it displays the previously entered number. I want to modify the code so that it takes alphabets only as input. How do. I do that plis help https://code.sololearn.com/coss8Dy9x1an/?ref=app

1/19/2022 9:11:39 AM

stephen haokip

9 Answers

New Answer

+2

You are reading a string and passing to Integer list by s = reader.readLine(); result.add(Integer.parseInt(s)); so it raise error. If you want add alphabets then change the list type....

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Jayakrishna🇮🇳 yep, your way is better.

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Jaya raising error when the input is alphabet is fine. But i want to modify the code so that it receive only alphabets as input and raise error when the user enters non alphabets

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It reads all as text by readLine(); whether alphabet or numbers.. Raising error is happening when you add to list. BufferReader only accept input as text.. if you want raise error if input is a number then use Scanner method... but numbers always can be read as text.. am I understanding wrong anything?

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Jayakrishna🇮🇳 if I understand correctly (and please, stephen haokip correct me for misunderstanding), the idea would be that the program checks to see if unacceptable characters, in this case non-alpha characters, are input. Then a warning would pop up. You know how passwords require caps and a number and a special character. This would be that only the alphabet is acceptable.

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BufferReader has 2 methods : readLine() which read a entire line of string. read() which reads a single character and returns it's ascii value. Both accept input as a text type.. you can read and type cast to needed type.. As you know that "abcde" is a string And "12345" is also a string & "@#₹_&+:;!? " is also a string.. All are valid inputs to readLine() And a, A, 1,2,&, #, +, .. these are all also single valid character type to be able to read by read() method. So those accept any input as a text or character types.. Non of " Integer, alphabets, special characters.. " are invalid input types .. So it won't raise error, until no input. So there, solution would be "accept input and check if it is alphabet or not. " If not raise error otherwise go on.. Hope it make sence, hope I understood your ideas stephen haokip Ausgrindtube edit @stephen read your last post that it actually misleading.. " raise error on alphabet is fine . but you want to raise error on non-alphabet? "

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I think what I'd do (and I think it's what Jayakrishna🇮🇳 is saying) stephen haokip is put in a Character.isDigit and similar for special characters and iterate through the string, throwing up an error when it's not an alpha. There might not be any other way because a String is for any character, whereas you can't have an input of nextInt and put a letter in.

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stephen haokip then I understood correctly.. And I posted the possible ways to do that with Bufferreader. One way is read character by read method and check by Character.isLetter(char) ; if it returns false then raise error manually... I think, isDigit() also works but it won't check for special chars.. I think it treats alphabets, special characters as both false.. depends on input, you can choose..

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Jaya... U dont get it it seems.. i have 2 codes... First one in my post... Second one is to be a modified version of the first... Raise error on alphabet is fine in first code... And in my modified version it should raise error on non alohabets