常见数据类型

Float f = 9.0f;
float ff = 9.0f;
Float fff = f + ff;

Double c = 7000.0;
double cc = 7000.0;
Double ccc = c + cc;

Short s = 2;
short ss = 2; 
Short sss = (short) (s + ss);

Integer i = 3;
int ii = 3;
Integer iii = i + ii;

Long l = 4L;
long ll = 4;
Long lll = l + ll;