CODEWITHSUNDEEP
javatypeswrapper
M. Santos
M. Santos

Reputation: 13

Is there a way to compare a primitive type with its corresponding wrapper type?

I have an ArrayList of objects ArrayList<Object> arrList containing wrapper classes for the various primitives as well as an array of type Parameter Parameter[] parameters

Both have the same number of elements. I would like to loop through the elements of parameters and compare that their types are the same as those in arrList.

I realise there are many ways of comparing an int with Integer.lang.Integer such as simply casting the int to an Integer and then comparing but my Parameter[] has ints, booleans, floats etc and my ArrayList has Integers, Floats, Booleans etc, so I am not always sure what the value will be. I don't think I really understand how primitives are represented. For example, I assumed the following statement would return true but it does not:

 Boolean bool=true;                                  
 System.out.println(boolean.class==bool.getClass());

I have this the relevant bit of code:

    for(int i=0; i<parameters.length; i++){
        if(parameters[i].getType()==arrList.get(i).getClass()){
           doSomething();
        }
    }

But the comparison always returns false even when it compares boolean.class to Boolean.getClass()

Thanks for any help/advice

Upvotes: 0

Views: 287

Answers (1)

Ricola
Ricola

Reputation: 2922

You can use the static field TYPE that every wrapper class has. (source)

for(int i=0; i<parameters.length; i++){
    if(parameters[i].getType()==arrList.get(i).getClass().getField("TYPE").get(null)){
       doSomething();
    }
}

You could also compare the lowercase class names but you would have to handle int and char as special cases.

Alternatively you could create a Map<Class, Class> between primitive classes and wrapper classes.

Upvotes: 1

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