Why does the code print undefined?

Question

function gainAcess(gender,age)
{
if ((gender=="male") && (age>=18) || (gender=="female") && (age>=18))
{ document.write("Access is gained");

}else if((gender=="male") && (age<18) ||(gender=="female") && (age<18)){
document.write("Access is lost");}
}

document.write(gainAcess("female",24));

Answer 1

Because the function doesn't return anything. If you want to write the output, return that output instead of writing it -- otherwise just call it instead of writing the result of the call. (too many writes, cut out one side):

function ... {
writes
}
gainAcess(...)

----- or:

function ... {
return "what to print";
}
document.write(gainAcess())

Answer 2

Thanks a lot.It worked with return statement :)))