Question

Is there a way to program "not" or "false"? For example, if x does not ==5:

Answer 1

Do mean checking if {something is not something} OR {if something is false}

Answer 2

i think i would mean if something is false, like the statement that x==5 is false in this example.

Answer 3

There is many ways to do that, it all depends on the problem at hand.

For example, if i wanted to see if x is 5, i would say.

if (x == 5)
{
//The true state
//Do something
}
else
{
//The false state
//DO something
}

Answer 4

i'm working on ps1, the 1000th prime number. How do I tell the program when my division test proves false, that the number is actually prime, then it should follow the second set of parameters?

I have tried the following (loosely)

if a%b==0:
procedure x
else: procedure y

When I try this, the IDLE highlights "else" and says it's an error in syntax.

Answer 5

The syntax of your loose example is correct.

Answer 6

if you wanted to see if x does not =5, and therefore is a prime number, you could say

if a%b!=0:
procedure y
you can avoid the else clause this way, because your syntax looks correct.

Answer 7

*even though your syntax looks correct

Answer 8

what does the ! mean?

Answer 9

!= == not equal
http://docs.python.org/library/stdtypes.html#comparisons
http://dpaste.com/710249/

Answer 10

if x != 5