After knowing primitive data types and Java rules of Data Type Casting (Type Conversion), let us cast long to boolean as an example.
The data type boolean is incompatible for converting into any other data type. That is, a boolean value cannot be converted (or assigned to) into any other data type like char, int, double, long etc. The maximum permitted is one boolean can be assigned to another boolean.
Following are not permitted.
int i1 = 10;
boolean b = i1; // error, int to boolean
boolean b = true;
int i1 = b; // error, boolean to int
char ch = 'A';
boolean b =ch; // error, char to boolean
boolean b = true;
long x = b; // error, boolean to long
Following is permitted (boolean assignment).
boolean b = true;
boolean b1 = b; // permitted
System.out.println(b1); // prints true
The keyword boolean is used in comparison operations.
int x = 10;
int y = 20;
boolean b = (x == y);
System.out.println(b); // prints false
Let us write a simple example to see how compiler react with boolean casting with long to boolean.
public class Conversions
{
public static void main(String args[])
{
long l1 = 65;
boolean b1 = l1; // compilation error
System.out.println(b1);
}
}
Error message screenshot of long to boolean Java
