void methodA() {
methodB(ClassA.class)
}
void methodB(Class classname) {
classname a; //not correct
HashMap<String, classname> hash = new HashMap<>(); //not correct
}
IDE is complaining it to be not correct.
I want to do something like what is being commented as //not correct. Why is it not correct and how can I do it?
You cannot use a variable name as a type name, so methodB won't compile.
You can however use a type parameter for the method. Try
<T> void methodB(Class<T> clazz) {
T a;
HashMap<String, T> hash = new HashMap<>();
}
methodB(ClassA.class) will still be the same? T is red. It asks me to create class T. Why is there a <T> before void methodB?
ClassA.class. It will control what type T is inferred to be.<T> declares a generic type parameter for the method, making T in scope for the method. This should work for Java 1.5+ (when generics were introduced).methodB, pass ClassA.class as an argument to methodB. In methodB, the parameter clazz is assigned the value passed in - ClassA.class.You can't use variable name as type of any method that has to passed as parameter. Else it will give compilation error.
