Short S = 1; S = S + 1; short S = 1; S + = 1; is there a difference ?? If so, what is the difference? If not, what is the value?

Short S = 1; S = S + 1; CompilationFailedShort S = 1; S + = 1; why can I compilePassSo? Another problem is that implicit type conversion can be automatically converted from small to large, that is, byte-> short-> int-> long. If the precision is lost in turn, it must be performed.Display type conversionS + = 1 means different from S = S + 1,

S = S + 1: Execute S + 1 first and then assign the result to S. Because 1 is of the int type, the return value of S + 1 is int,
The compiler automatically performs implicit type conversion. Therefore, an error occurs when an int type is assigned to short,

S + = 1 is different because it is the + = Operator. in parsing, S + = 1 is equivalent to S = (short) (S + 1). Doubling is
S + = 1 <=> S = (S type) (S + 1)