Question from Dan's test on Char values

class D {
public static void main (String[] args) {
char a = 061; // 1
char b = '\61'; // 2
char c = '\061'; // 3
char d = 0x0031; // 4
char e = '\u0031'; // 5
System.out.print(""+a+b+c+d+e);
}
}
Ans:Compiles & runs fine.
At line one octal integer is converted to char.
At line 4 hexadecimal integer is assigned.
At line 5 unicode character is assigned.
But I am not understanding what is happening at lines 2 & 3?What is the role of back slash there?
Thanks
Veena

both lines 2 and 3 are octals also. The backslash allows you to place the octal digits there. I asked a similar question a couple weeks ago. If you do a search you should be able to find it. I think someone posted a link when they responded explaining it.
I wouldn't worry about it being on the exam though.

'\001' '\01' '\1'
'\012' '\12'
"This is \u0061 string of text with escape sequences for some of the ch\141racters.\n"
Some ASCII characters we can type �A� �a� �0� �*�
Some ASCII characters we cannot type. So we use escape sequences instead. �\n� �\r� �\\� �\��
�0� is the decimal digit 0. How do we represent binary 0?
We can use octal escape sequences to type any ASCII character.
�\000� �\007� �\017� �\077� �\177� �\377�
What are octal escape sequences good for? Control characters for data communications (end-of-text, end-of-line) and talking to devices (ring-bell, form feed)
There are 65536 Unicode characters. Only the first 256 Unicode characters can be represented by octal escape sequences.
(Actually, I think there are at least 90,000 currently defined Unicode characters.)
[ July 18, 2003: Message edited by: Marlene Miller ]

Originally posted by Marlene Miller:
�\u0000� 0x0000 0x00 0 '\000' �\u0001� 0x0001 0x01 1 '\001' �\u0008� 0x0008 0x08 8 '\010' �\u0009� 0x0009 0x09 9 '\011' �\u000a� 0x000a 0x0a 10 '\012' �\r� �\u000d� 0x000d 0x0d 13 '\015' �\n� �\u0010� 0x0010 0x10 16 '\020' �\u0020� 0x0020 0x20 32 '\040' �0� �\u0021� 0x0021 0x21 33 '\041' �1� �\u0041� 0x0041 0x41 65 '\101' �A� �\u0061� 0x0061 0x61 97 '\141' �a� �\u00ff� 0x00ff 0xff 255 '\377'
'\001' '\01' '\1'
'\012' '\12'
"This is \u0061 string of text with escape sequences for some of the ch\141racters.\n"
Some ASCII characters we can type �A� �a� �0� �*�
Some ASCII characters we cannot type. So we use escape sequences instead. �\n� �\r� �\\� �\��
�0� is the decimal digit 0. How do we represent binary 0?
We can use octal escape sequences to type any ASCII character.
�\000� �\007� �\017� �\077� �\177� �\377�
What are octal escape sequences good for? Control characters for data communications (end-of-text, end-of-line) and talking to devices (ring-bell, form feed)
There are 65536 Unicode characters. Only the first 256 Unicode characters can be represented by octal escape sequences.
(Actually, I think there are at least 90,000 currently defined Unicode characters.)
[ July 18, 2003: Message edited by: Marlene Miller ]

Does '\0some number' & '\some number' represent octal representation?& '\u0some number' represent hexadecimal?