Assignments between different primitive numeric types

A value of a given type cannot be assigned to a variable of a data type with a smaller size, because we would risk to lose information. Moreover, a floating point value cannot be assigned to an integer variable.

The following table describes whether the assignment a=b is legal, for each possible type for a (on the rows) and b (on the columns).

a=b	byte	short	int	long	float	double
byte	OK	ERROR	ERROR	ERROR	ERROR	ERROR
short	OK	OK	ERROR	ERROR	ERROR	ERROR
int	OK	OK	OK	ERROR	ERROR	ERROR
long	OK	OK	OK	OK	ERROR	ERROR
float	OK	OK	OK	OK	OK	ERROR
double	OK	OK	OK	OK	OK	OK

Example:

• int a; long b; a = b;
  Error: a value of type long cannot be assigned to a variable of type int.
• int a; float b; a = a + b;
  Error: the expression a+b is of type float, and a value of type float cannot be assigned to a variable of type int.