Is there a fancy way to cast an Integer array to an int array? (I don't want to iterate over each element; I'm looking for an elegant and quick way to write it)
The other way around I'm using
scaleTests.add(Arrays.stream(data).boxed().toArray(Double[]::new));
I'm looking for an one-liner but wasn't able to find something.
The goal is to:
int[] valuesPrimitives = <somehow cast> Integer[] valuesWrapper
您可以使用 Java 8 的 Stream API
int[] intArray = Arrays.stream(array).mapToInt(Integer::intValue).toArray();
If you can consider using Apache commons ArrayUtils then there is a simple toPrimitive API:
public static double[] toPrimitive(Double[] array, double valueForNull)
Converts an array of object Doubles to primitives handling null.
This method returns null for a null input array.
Using Guava, you can do the following:
int[] intArray = Ints.toArray(intList);
If you're using Maven, add this dependency:
<dependency>
<groudId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>18.0</version>
</dependency>
如果您有权访问 Apache lang 库,那么您可以使用 ArrayUtils.toPrimitive(Integer[]) 方法,如下所示:
int[] primitiveArray = ArrayUtils.toPrimitive(objectArray);
You can download the org.apache.commons.lang3
jar file which provides ArrayUtils
class.
Using the below line of code will solve the problem:
ArrayUtils.toPrimitive(Integer[] nonPrimitive)
Where nonPrimitive
is the Integer[]
to be converted into the int[]
.
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