Formatting using printf and format

Question

In the following program

class ZiggyTest2 {

    public static void main(String[] args){     

        double x = 123.456;
        char c = 65;
        int i         


        

Answer 1

for "%b" : If the argument arg is null, then the result is "false". If arg is a boolean or Boolean, then the result is the string returned by String.valueOf(). Otherwise, the result is "true".

reference

Answer 2

Because the value is of type double and this is how the %b converter works with values of this type.

Answer 3

The API documentation seems to clearly state why.

If the argument arg is null, then the result is "false". If arg is a boolean or Boolean, then the result is the string returned by String.valueOf(). Otherwise, the result is "true".