Why explicit cast required when adding int with byte?

Question

Doing this is legal in Java

byte = 27     // 27 treated as int; implicit cast to byte

But when assigning a value as a result of expression, Java requires explicit casting

int a = 9;
byte b = 8;
byte c = a + b;  // Compile error

What is the reason behind this?

score 2 · Accepted Answer · answered Jul 12 '15 at 20:31

2

27 is a literal. The compiler knows that it is representable in a byte (from -128 to 127).

a + b is an expression involving variables. Its result may not be representable in a byte

answered Jul 12 '15 at 20:31

M A

1

That is a great answer. Because I tried byte c = 9 + 8 and it worked. Thanks – Vivin Jul 12 '15 at 20:35
Yes this is just `c = 17` for the compiler. – M A Jul 12 '15 at 20:44

1 Answers1