How can I get the last character of a users input?

Question

System.out.print("Enter a sentence: ");
String sentence = kb.readLine();
int sLength = sentence.length();

if (sentence.charAt(sLength).equals('?')
    System.out.println("Yehey!!!!!");

I'm trying to get the last character and compare it to "?", my code doesn't work. How can I solve the problem?

.chatAt(sLength) will throw an IndexOutOfBoundsException... Ranges go from 0 to n - 1. Also, this returns a `char` which is a primitive type: use `==`. `sentence.charAt(sLength - 1) == '?'` — fge, Dec 01 '14 at 13:42
You need to learn that in programming numbers start with 0, not 1. — nikoliazekter, Dec 01 '14 at 13:42
@Maroun Maroun ok sorry, i'm not programming languages polyglot. — nikoliazekter, Dec 01 '14 at 17:43

Maroun · Accepted Answer · 2014-12-01T13:47:19.047

7

Should be:

sentence.charAt(sLength - 1) == '?'
                        ↑ 
                    Your savior

You need -1 because if the String of length N, then the last character is at place N - 1:

String#charAt:

Returns the char value at the specified index. An index ranges from 0 to length() - 1

Also note that it returns a char, and not a String. Since char is a primitive, you cannot invoke equals, == is just fine.

edited Dec 01 '14 at 13:47

answered Dec 01 '14 at 13:42

Maroun

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"arrays are zero-based" <-- not really; if a `String` is a char array, `.charAt()` is specified by `CharSequence` – fge Dec 01 '14 at 13:44
Which is backed up with array, no? – Maroun Dec 01 '14 at 13:45
ohhh!!!! great!!! i hadnt known about it!!! thank you so much... actually you are my savior... so basically what does -1 mean??? – Rae Dec 01 '14 at 13:46
No, it doesn't have to be. [this project](https://github.com/fge/largetext) implements `CharSequence`, for instance, and is not backed by an array – fge Dec 01 '14 at 13:46
@Rae It means minus one, if your string is "hello_world", then "d" is at the 10th place. – Maroun Dec 01 '14 at 13:46
@MarounMaroun , i see because in counting characters it starts with 0??? – Rae Dec 01 '14 at 13:48
@MarounMaroun great!!!! i learn something now!!! thank you so much.... :D have a nice day ahead – Rae Dec 01 '14 at 13:50
@Rae , You should then accept this answer as it answered your question – Spikatrix Dec 01 '14 at 13:52

score 0 · Answer 2 · edited Dec 01 '14 at 14:05

0

The correct way is:

if (sentence.charAt(sLength-1).equals('?')
        System.out.println("Yehey!!!!!");

Because the last char of a string is ( array.length() - 1 )

edited Dec 01 '14 at 14:05

Bence Kaulics

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answered Dec 01 '14 at 13:46

Husseinfo

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NO. `.charAt()` returns a `char`, not a `String`. – fge Dec 01 '14 at 13:47
yes i know :) but String is a an array of char, so the index of its last element is its length - 1 – Husseinfo Dec 01 '14 at 13:50

score -1 · Answer 3 · answered Dec 01 '14 at 14:04

-1

should be:

       sentence.charAt(sLength - 1) == '?'

answered Dec 01 '14 at 14:04

thinkinjava

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How can I get the last character of a users input?

3 Answers3