First letter of String to Char

Question

What I have is a student with a name and firstletter

So I have a class student like:

private String name = "Unknown";

private char nameLetter = "u"; 

public void identify()
{
    System.out.println("Student first letter : " + nameLetter);
    System.out.println("Student name : " + name);

}

public void setName(String newName)
{
    name = newName;
    nameLetter = newName.substring(0);
}

But i get the error cant convert from string to char.

I know I could make a String nameLetter instead of char but I want to try it with char.

Use single quotes when use `char`, like: `char nameLetter = 'u';` — dic19, Sep 19 '13 at 13:26
This is where your IDE would tell you which methods of String return a `char` (assuming you don't want to read the Javadoc) — Peter Lawrey, Sep 19 '13 at 13:29

Sergey Kalinichenko · Answer 1 · 2013-09-19T13:28:10.470

7

You need this:

nameLetter = newName.charAt(0);

Of course you must check that newName's length is at least 1, otherwise there would be an exception:

public void setName(String newName) {
    name = newName;
    if (newName != null && newName.length() > 0) {
        nameLetter = newName.substring(0);
    } else {
        nameLetter = '-'; // Use some default.
    }
}

edited Sep 19 '13 at 13:28

answered Sep 19 '13 at 13:26

Sergey Kalinichenko

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Why do you use newName != null isn't it impossible to call the method without a parameter? (just asking not trying to be smart) – Sven van den Boogaart Sep 19 '13 at 13:36
@SvenB One cannot call it without a parameter, but it is perfectly possible to pass `null` instead of a `String` (not good, but possible). Like this: `myObj.setName(null);` Without a `null` check the method would throw an exception. – Sergey Kalinichenko Sep 19 '13 at 13:38
Would except you answer if it mentioned "u" is a string literal, 'u' a char. thx anyway the other answer didnt post the filter you had. so i upvoted it anyway but else you were the answer – Sven van den Boogaart Sep 19 '13 at 15:04
@SvenB "accept you answer if it mentioned "u" is a string literal, 'u' a char" I thought the compiler has already told you that ;-) – Sergey Kalinichenko Sep 19 '13 at 15:49

Bathsheba · Accepted Answer · 2013-09-19T14:16:17.997

4

"u" is a string literal, 'u' a char.

Specifally, you need to replace nameLetter = newName.substring(0); with nameLetter = newName.charAt(0); as the former returns a string, the latter a char.

edited Sep 19 '13 at 14:16

answered Sep 19 '13 at 13:26

Bathsheba

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Reimeus · Answer 3 · 2013-09-19T13:33:02.707

1

Enclose character primitives with ' instead of "

private char nameLetter = 'u';

Use charAt instead of substring for extracting characters from Strings

nameLetter = newName.charAt(0);

Read: Characters

edited Sep 19 '13 at 13:33

answered Sep 19 '13 at 13:26

Reimeus

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score 1 · Answer 4 · edited May 23 '17 at 10:25

1

nameLetter = newName.toCharArray[0];

or you can try

nameLetter = newName.charAt[0];

To know the difference between both this approaches, you can see the answers to this question

edited May 23 '17 at 10:25

Community

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answered Sep 19 '13 at 13:27

Farax

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score 0 · Answer 5 · answered Sep 19 '13 at 13:26

0

try

nameLetter = newName.charAt(0);

answered Sep 19 '13 at 13:26

upog

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score 0 · Answer 6 · answered Sep 19 '13 at 13:27

0

You may want to look into the String#charAt(int) function.

answered Sep 19 '13 at 13:27

BambooleanLogic

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First letter of String to Char

6 Answers6