Java implicit conversion

Use the following code:

Float a = 1.2;

There is an error because it takes decimal as the value of double, which is a larger data type than float

It now takes integers as the default int type So why doesn't the following code give any errors?

Byte b = 20;

Solution

The compiler is smart enough to make sure that the 20 bit representation (int value) can fit a byte without losing data From Java language specification § 5.1 3：

See also this thread