Int type changed to double

Although a small range of types to a large range of types can Implicit conversion , But when there is an expression operation, you need Coercive transformation , Otherwise, accuracy may be lost .

Left to right range From small to large ：byte->short->int->long->float->double

for example ：

int a = 1;

double b = a/2;  // The result is 0

double c = (double)a/2;  // The result is 0.5

stay Java Two of them int Divide the numbers of type , Take the whole part , The decimal part is directly rounded off , As above a/2.

If there are two types in the expression , The results are subject to the large type .

for example ：

int a = 1;

double b = 2.0;   //double Assignment can be written 2, Can also write 2.0, Can also write 2d, perhaps 2.0d

double c = a/b;    The result is 0.5 ,// The result is no longer forced