= Time and Math

== Time

== isEven
<Code:Python>
def main():
    a = 5

    if iseven(a):
        print(f"{a} is even.")
    else:
        print(f"{a} is odd.")

def iseven(a):
    return True

if __name__ == "__main__":
    main()
</Code>

We'll start by fixing this. Then, we'll make a function that tests if a number is prime. Then we will try to generate the first million prime numbers. But, quickly!

=== other isEven
def iseven_bad(a):
    b = float(a) / 2
    c = str(b)
    d = c[-1]

    if d == '0':
        return True

    return False

def iseven_good(a):
    b = a % 2
    if b == 0:
        return True

    return False

def iseven_bit(a):
    if a & 1:
        return False
    else:
        return True

def iseven_count(a):
    b = a
    while b > 0:
        b = b - 2
        if b == 1:
            return False

    return True

</Code>

=== Testing
<Code:Python>
def test():
    # set up the array
    a = []
    for x in range(1_000_000):
        a.append(random.randint(1,1000))

    start = time.perf_counter_ns()

    c = 0
    for x in range(1_000_000):
        r = iseven_good(a[c])
        c = c + 1

    ms = (time.perf_counter_ns() - start) / 1_000_000
    print(f"run time: {ms} ms")

</Code>