Java Utililty Methods Array Size Get

int arraySize(final int expected, final float f)
array Size

final long s = Math.max(2L, nextPowerOfTwo((long) Math.ceil((double) ((float) expected / f))));
if (s > 1073741824L) {
 throw new IllegalArgumentException(
 "Too large (" + expected + " expected elements with load factor " + f + ")");
} else {
 return (int) s;

int arraySize(final int expected, final float f)
Returns the least power of two smaller than or equal to 2³⁰ and larger than or equal to Math.ceil( expected / f ).

final long s = nextPowerOfTwo((long) Math.ceil(expected / f));
if (s > (1 << 30))
 throw new IllegalArgumentException(
 "Too large (" + expected + " expected elements with load factor " + f + ")");
return (int) s;

long arraySizeOf(int[] array)
array Size Of

if (array == null)
 return 0;
return calArraySize(array.length, SIZE_OF_INT);