Error in determine positive\negative number in JAVA -

below snippet find sign(+/-) of number without using > or < conditional operators basically!

    scanner s = new scanner(system.in);     int n = s.nextint(); /**take user input /      /* stretch user input either of infinity  */     n *= double.negative_infinity;      /* compare result */     if(n == double.negative_infinity)     {      system.out.println("number positive ");     }     else if (n == double.positive_infinity )     {         system.out.println("number negative" );       }     else     {         system.out.println("could not determine number type!!" );     } 

i added

system.out.println("nmbr , negtive infinity : "+n+" "+double.negative_infinity); 

for user input : -12, shows :

/* ideally should "infinity -infinity" according me */ nmbr , negtive infinity : 2147483647 -infinity  

after doing multiplication see resultant value, reason. dont nmbr equal infinite value

2 questions :

• when taking int type input, getting promoted double type on multiplication??

• whats wrong above logic?? , getting output :

could not determine number type!!

you have implicit cast in code. this:

n *= double.negative_infinity; 

is equal to:

n = (int) (n * double.negative_infinity); 

n int in code snippet, double.negative_infinity double, result of calculation double. after because saving result in int variable, result gets downcasted int. ints not have infinity, double gets casted highest possible integer: integer.max_value == 2147483647.
it obvious number not infinity.

if change n double, code working