Using xor or bit shifts with datatype char

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ryanf11

Using xor or bit shifts with datatype char

in Programming Questions • 4 months ago

Hi,

I'm trying to use multiply(*), xor (^) and bit shift left(<<) on character data types (ex buf4 = (x<<2), buf4 = x*4, buf1 = state[buf4] ^ state[buf4+1], and so on). But when I do so, I get the error "cannot convert from int to char". I thought the problem could be the integer values used in the equations, but even without them the same error persists. Are character data types incapable of these functions?

Thanks,

Ryan

Replies(2)

tfguy44

Re: Using xor or bit shifts with datatype char

4 months ago

You should be able to do these sorts of operations on characters (as they are indeed stored in binary), but you might have to cast the results back to characters before storing them:

char buf4;
char x = 'a';
println( binary( x ) );
buf4 = char(x<<2);
println( binary( buf4 ) );
buf4 = char(x*4);
println( binary( buf4 ) );

GoToLoop

Re: Using xor or bit shifts with datatype char

4 months ago

It's 1 of the few things I still hate about Java!

All operands are at minimum converted to data-type int before any calculation!

Thus, the following data-types -> byte, short, char become int when doing math!

And normal assignments fail; b/c Java doesn't fix its mess back to original data-type as C/C++/D do!

Here's an example of it:

char a = 10, b = 30;

char c = a + b;    // <- cannot convert from int to char

println(c);

Both variables a & b are of data-type char. However, their extracted values

are converted to int before doing the + operation!

You have to use a cast operator (or a conversion function) for the resulting calculation:

char a = 10, b = 30;

char c = (char) (a + b); // <- Now it works!

println(c);

exit();

It's funny a composite assign (operation & assignment) has auto-box conversion:

char a = 10, b = 30;

b += a; // <- auto-conversion!

println(b);

exit();

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