Adding numbers in Java?

For adding numbers of the same type we have to first define the variables. Like in the below code we define two variables of type int. 

int i=5;  
int j=10;

int sum = i + j;

System.out.println(sum);

For adding numbers which have different types; int i=5; float j=10;

float sum = i + j;

System.out.println(sum);

Sum variable type should be in float (data type)