How does Java concatenate 2 lines?

Question

Why is the next print 197 but not "bc"?

System.out.println('b' + 'c');

Can someone explain how to do proper concatenation in Java?

PS I have learned some Python and am now moving on to learning Java.

+3

user2988464 Feb 10 '14 at 5:04

6 answers

'b'is not Stringin Java, it is char. Then 'b'+'c'prints 197.

"b"+"c", bc, "" String.

System.out.println("b" + "c"); // prints bc

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+ char ascii , , . bc , b c String. b c char Java.

Java "", ''

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, Char, :

System.out.println("b" + "c");

:

"" + char1 + char2 + char3;

new StringBuilder().append('b').append('c').toString();

+1

Zaheer Ahmed 10 . '14 5:09

Java Strings - ""

char. :

System.out.println("b" + "c"); // bc

, , ASCII chars, 197.

ASCII 'b' 98, ASCII 'c' 99.

:

System.out.println('b' + 'c'); // 98 + 99 = 197

ASCII chars:

char - 16- .

Docs. (0-255), , chars ASCII, ASCII - . .

, ASCII , , 256 ASCII ( ) - .

, , - ASCII ( Unicode). Unicode.

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'b' 'c' , . 197 - unicode b c

Concatinating String :

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Rakesh KR 10 . '14 5:14

Christian · Accepted Answer · 2014-02-10T05:05:24+0000

'b'and 'c'not Strings, they are chars. Instead, use double quotes "...":

System.out.println("b" + "c");

You get intbecause you add the unicode values of these characters:

System.out.println((int) 'b'); // 98
System.out.println((int) 'c'); // 99
System.out.println('b' + 'c'); // 98 + 99 = 197