primitive

Possible Duplicate: Arrays.asList() not working as it should? Apparently the return type of Arrays.asList(new int[] { 1, 2, 3 }); is List<int[]> . This seems totally broken to me. Does this have something to do with Java not autoboxing arrays of primitive types? The problem is that Arrays.asList takes a parameter of T... array . The only applicable T when you pass the int[] is int[] , as arrays of primitives will not be autoboxed to arrays of the corresponding object type (in this case Integer[] ). So you can do Arrays.asList(new Integer[] {1, 2, 3}); . Try: Arrays.asList(new Integer[] { 1, 2,

MDN states: primitive, primitive value A data that is not an object and does not have any methods. JavaScript has 5 primitive datatypes: string, number, boolean, null, undefined. With the exception of null and undefined, all primitives values have object equivalents which wrap around the primitive values, e.g. a String object wraps around a string primitive. All primitives are immutable. So when we call a "s".replace or "s".anything is it equivalent to new String("s").replace and new String("s").anything ? No, string primitives do not have methods. As with numeric primitives, the JavaScript

public class Foo { public static void main(String[] args) { float f; System.out.println(f); } } The print statement causes the following compile-time error, The local variable f may not have been initialized If primitives in Java already have a default value (float = 0.0f) , why am I required to define one? Edit: So, this works public class Foo { float f; public static void main(String[] args) { System.out.println(new Foo().f); } } Thanks, everyone! Because it's a local variable. This is why nothing it's assigned to it : Local variables are slightly different; the compiler never assigns a

I need to make some reflective method calls in Java. Those calls will include methods that have arguments that are primitive types (int, double, etc.). The way to specify such types when looking up the method reflectively is int.class, double.class, etc. The challenge is that I am accepting input from an outside source that will specify the types dynamically. Therefore, I need to come up with these Class references dynamically as well. Imagine a delimited file a list of method names with lists of parameter types: doSomething int double doSomethingElse java.lang.String boolean If the input was

There are related questions, such as How can I pass in 2 parameters to a AsyncTask class? , but I ran into the difficulty of trying in vain to pass multiple primitives as parameters to an AsyncTask, so I want to share what I discovered. This subtlety is not captured in the existing questions and answers, so I want to help out anyone who runs into the same problem as I did and save them the pain. The question is this: I have multiple primitive parameters (e.g. two longs) that I want to pass to an AsyncTask to be executed in the background--how can it be done? (My answer...after struggling with

In C++, I enjoyed having access to a 64 bit unsigned integer, via unsigned long long int , or via uint64_t . Now, in Java longs are 64 bits, I know. However, they are signed. Is there an unsigned long (long) available as a Java primitive? How do I use it? Sean Bright I don't believe so. Once you want to go bigger than a signed long, I think BigInteger is the only (out of the box) way to go. Starting Java 8, there is support for unsigned long (unsigned 64 bits). The way you can use it is: Long l1 = Long.parseUnsignedLong("17916881237904312345"); To print it, you can not simply print l1, but you