I'm writing a method that prints every Object that is passed to it. This works fine by calling the Object.toString()
method for the object but doesn't work for arrays. I can find out whether it is an Array with the Object.getClass().isArray()
method, but I don't know how to cast it.
int[] a;
Integer[] b;
Object aObject = a;
Object bObject = b;
// this wouldn't work
System.out.println(Arrays.toString(aObject));
System.out.println(Arrays.toString(bObject));
If you don't know the type you can cast the object to Object[]
and print it like this (after making sure it is indeed an array and can be cast to Object[]
). If it is not an instance of Object[]
then use reflection to create an Object[]
first and then print:
private void printAnyArray(Object aObject) {
if (aObject.getClass().isArray()) {
if (aObject instanceof Object[]) // can we cast to Object[]
System.out.println(Arrays.toString((Object[]) aObject));
else { // we can't cast to Object[] - case of primitive arrays
int length = Array.getLength(aObject);
Object[] objArr = new Object[length];
for (int i=0; i<length; i++)
objArr[i] = Array.get(aObject, i);
System.out.println(Arrays.toString(objArr));
}
}
}
TESTING:
printAnyArray(new int[]{1, 4, 9, 16, 25});
printAnyArray(new String[]{"foo", "bar", "baz"});
OUTPUT:
[1, 4, 9, 16, 25]
[foo, bar, baz]