What's the difference "c=c+1" vs "c+=1"

[Sam Bai]

The code below can print out 'b'
char c='a';
c+=1;
System.out.println(c);
Why the code below cannot compile?
char c='a';
c=c+1;
System.out.println(c);
Thanks a lot!

[Saniya Ansari]

This is because when u do the operation c + 1 the c is converted to int to carry out the opeartion. To assign it back to a char type u need to have an explicit cast since int is a 32 bit data type while char is 16 bit.
In the extended operators this is done automatically. Coz the extenede operator looks like this: c= (char)(c+1); so this will do the job.
Hope this will be of help!

[Valentin Crettaz]

Heng630,
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[Barkat Mardhani]

posted by Saniya:

This is because when u do the operation c + 1 the c is converted to int to carry out the opeartion. To assign it back to a char type u need to have an explicit cast since int is a 32 bit data type while char is 16 bit.

Furthermore, the mentioned explicit cast can be avoided if RHS is composed of literals and/or final variables which results in a value that is within the range of LHS type. See following code which compiles o.k.:

class Test {
public static void main(String[] args) {
final char c = 2; // line 1
char d = 3;
d = c + 1; // line 2
}
}