Typecasting from int to char and ASCII values

Question

int a1 = 65535;

char ch2 = (char) a1;

System.out.println(\"ASCII value corresponding to 65535 after being typecasted : \"+ch2);// prints?
char ch3 = 65535;
System.         


        

Answer 1

About why char ch22 = (char) a11 works

From java specification

A narrowing primitive conversion may lose information about the overall magnitude of a numeric value and may also lose precision and range.

[...]

A narrowing conversion of a signed integer to an integral type T simply discards all but the n lowest order bits, where n is the number of bits used to represent type T. In addition to a possible loss of information about the magnitude of the numeric value, this may cause the sign of the resulting value to differ from the sign of the input value.

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About why char c = 65536 doesn't work

From java specification

A narrowing primitive conversion followed by a boxing conversion may be used if the type of the variable is:

• Byte and the value of the constant expression is representable in the type byte.
• Short and the value of the constant expression is representable in the type short.
• Character and the value of the constant expression is representable in the type char.

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65536 is not inherently a char value

For example

• 1 is at the same time a byte, a short, a char, an int and a long value.
• 256 is a short, char, int and long value, but not a byte value.
• 65535 is a char, int and long value, but neither byte nor short value.
• -1 is a byte, short, int, long value, but not a char value.
• 65536 is only an int and long value.

char c = (char)65536; will work