Create a type-safe generic array.
* - *Arrays are covariant i.e. they cannot be created from a generic type:
+ *The Java language does not allow an array to be created from a generic type:
* *
public static <T> T[] createAnArray(int size) {
- return T[size]; // compiler error here
+ return new T[size]; // compiler error here
}
public static <T> T[] createAnArray(int size) {
return (T[])new Object[size]; // ClassCastException at runtime
}
*
*
- * Therefore new arrays of generic types can be created with this method, e.g. an arrays - * of Strings:
+ *Therefore new arrays of generic types can be created with this method. + * For example, an array of Strings can be created:
* *
String[] array = ArrayUtils.toArray("1", "2");
String[] emptyArray = ArrayUtils.<String>toArray();
*
*
- * The method is typically used in scenarios, where the caller itself uses generic types
- * that have to be combined into an array.
+ * The method is typically used in scenarios, where the caller itself uses generic types + * that have to be combined into an array.
* - * Note, this method makes only sense to provide arguments of the same type so that the + *Note, this method makes only sense to provide arguments of the same type so that the
* compiler can deduce the type of the array itself. While it is possible to select the
- * type explicitly like in Number[] array = ArrayUtils.<Number>toArray(new
- * Integer(42), new Double(Math.PI)), there is no real advantage to new
- * Number[] {new Integer(42), new Double(Math.PI)} anymore.
+ * type explicitly like in
+ * Number[] array = ArrayUtils.<Number>toArray(new Integer(42), new Double(Math.PI)),
+ * there is no real advantage when compared to
+ * new Number[] {new Integer(42), new Double(Math.PI)}.