Java Utililty Methods Factorial

return FACTORIALS[n];

int returnValue;
if (n < 0) {
    throw new IllegalArgumentException("Illegal value: " + n);
} else if ((n == 0) || (n == 1)) {
    returnValue = 1;
} else {
    returnValue = n * factorial(n - 1);
return returnValue;

if (n < 0 || (n - (int) n) != 0)
    throw new IllegalArgumentException(
            "\nn must be a positive integer\nIs a Gamma funtion [gamma(x)] more appropriate?");
double f = 1.0D;
for (int i = 1; i <= n; i++)
    f *= i;
return f;

return binomialCoefficient(n, 1);

if (number <= 1) {
    return 1;
} else {
    return number * factorial(number - 1);

if (value > 12) {
    throw new IllegalStateException("The value[" + value
            + "] is greater than 12 and anything equal to or larger than 13! is too large to be returned as an int.");
} else if (value < 0) {
    throw new IllegalStateException(
            "The value[" + value + "] is less than 0, so factorial cannot be computed.");
int result = 1;
...

return Math.pow(10, log10Gamma(x + 1));

if (x == 0 || x == 1) {
    return 1;
} else if (x > 0) {
    int mul = 2;
    for (int i = 3; i <= x; i++) {
        mul *= i;
    return mul;
...

long result = 1;
while (x >= 1) {
    result *= x;
    x--;
return result;

if (l <= 2)
    return l;
return l * factorial(l - 1);