Boolean instanceof Object is true?
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21-09-2019 - |
Question
I've been learning Java in my spare time and have a quick question I can't seem to figure out. This code returns true:
Boolean testBool = true;
Boolean test = testBool instanceof Object;
System.out.println(test);
However, I thought Boolean was a primitive type and when I try this same logic with any other primitive type I get a compiler error that says: unexpected type required: reference found: int
I'm sure there's just something small I'm missing. Thanks for your help!
Solution
boolean is a primitive type; java.lang.Boolean is its wrapper class.
You'll notice that all the primitive types have companion wrapper classes (e.g., int and java.lang.Integer, etc.)
OTHER TIPS
Boolean
with uppercased initial B
wraps a boolean
primitive. As the docs say:
The Boolean class wraps a value of the primitive type boolean in an object. An object of type Boolean contains a single field whose type is boolean.
Autoboxing can implicitly move between such boxed types and the corresponding primitives.