I'm working on a problem learning to use "if" statements, and the code is supposed to tell us if a given number is positive or negative by resulting in "True" or "False". Having some trouble identifying how to output this correctly, and I believe it is because I don't fully understand return() statements yet.
Here is the code so far:
def is_positive(number):
if (number) > 0:
return number
The above returns "13" when given is_positive(13), I think I'm just a little lost on how to tell the code to return "True/ False?"
Apologies if I am missing something completely obvious here. Thanks!
Also still getting used to stack overflow searching, so any tips appreciated if this is a common question!
You can simply change the return statement to return True or return False.
Just change your return statement to
return (number) > 0
Related
I have a question related to a transition in my statechart (see image above). I have a variable called palletInUse which is a boolean-type and changes between true and false. For one transition in my statechart I want it to change when the variable palletInUse has the value true. I have tried it with for example:
palletInUse == true;
and also tried different code like, equals and contentEquals etc. but nothing seems to work. Do you have a solution for this, seemingly simple problem?
Thanks in advance
The condition is not monitored constantly, only when something is changed in the agent. When you assign a new value to variable with common "=" Java operator, it is not caught by the AnyLogic engine. You need to call onChange() function after that. Then, the transition should be executed.
There are other ways to trigger the condition check without explicit onChange() call. You may find them in AnyLogic Help article.
BTW, you may specify just boolean variable as the condition, it is not required to compare it with true or false:
palletInUse
The condition is not evaluated if nothing is happening, for that reason you have to make something happen constantly to have your condition evaluated. A typical way of doing is as you see in the following pictures:
i have searched for a simple, non complicated answer on how to ensure that the user is asked again if they enter anything other than text for 1 and an integer for 2.
when entering these input variables, however i have only found complicated solutions that my teacher wont acccept.
is it possible if anyone can provide me with simple solutions on how to validate these variables. so far all i know how to validate is to use "while not in" functions, which only works for specific options. I am new to python, so please explain in a simple manner. thanks! :)
1-studentname=input("what is your name?:")
2-print("what is 10+10?:")
3-studentanswer=int(input("insert answer:"))
You can use a while loop with if , else in it
while(true):
t = int(input());
if t == 1:
# do whatever --> break at the end
else if t == 2:
# do whatever ---> break at the end
else:
continue
You can use the .isalpha and .isdigit method.
For example,
studentname=input("what's your name) ?
studentname.isalpha()
That checks whether the string consists of alphabetic characters only.
Both .isalpha and .isdigit return boolean, so you can use an if condition then.
I think this is a really general programming question, since boolean syntax is more or less the same in a lot of common languages.
But still my question is for php and javascript mainly.
Suppose I want to write an if statement which returns true if a variable is equal to 2,3, or 5.
And this variable has a very long name, so like this:
if((An_Object_With_A_Long_Name.Has_Also_An_Array[With_An_Index_Too]==2)
|| (An_Object_With_A_Long_Name.Has_Also_An_Array[With_An_Index_Too]==3)
||(An_Object_With_A_Long_Name.Has_Also_An_Array[With_An_Index_Too]==5))
{
return true;
}
and I really want my code look shorter, it is less depressing to read it months after :)
so can I simplify this into something like
if(An_Object_With_A_Long_Name.Has_Also_An_Array[With_An_Index_Too]==2||3||5)
Thanks for help !
Cheater way out: For that if statement, assign An_Object_With_A_Long_Name to Object i. (If you plan to have to compare this variable several times, assign Object i the pointer of An_Object_With_A_Long_Name.
Was wondering if someone could lend me their expertise. Pretty new to Vb.net and have come across this conditional statement in one of our products. Could someone please confirm the validity of the statement and explain what's going on here? I've tried numerous searches, but I cannot find anything related.
If (IsDBNull(dr("someID")), "0", dr("someID")) = someID.ToString() Then
I have changed the "id" value names as it's code from a commercial product, but the ID's used were all the same variable (ints).
Thanks for any input you can offer on this!
Joe
PS: The reason I can't check this at run time is because of how the product operates.
It is an inline If statement
If(condition,iftrue,iffalse) if condition is true evaluate and return iftrue else iffalse
The If operator in VB.NET 2008 acts as a ternary operator.[ REFERENCE]
Example:
Dim foo as String = If(bar = buz, cat, dog) 'Condition satisfied then it'll return cat else dog.
The statement is checking to see if the dr("SomeID") equals the value someID.ToString. The reason the If is required is because you need to check if the dr("someID") Is Null. If it is 0 is used instead which presumably should not be equal to someID.
It is the same as doing the following:
If Not IsDBNull(dr("someID")) Then
If dr("someID").ToString = someID.ToString Then
End If
End If
I would suggest that something like this would be more appropriate (checking integer values instead of comparing strings)
If(IsDBNull(dr("someID")), 0, CInt(dr("someID"))) = someID Then
I would also suggest Turning Option Strict On as the code you posted should not compile!
Here is the single line from one of my functions to test if any objects in my array have a given property with a matching value
Return ((From tag In DataCache.Tags Where (tag.FldTag = strtagname) Select tag).Count = 1)
WHERE....
DataCache.Tags is an array of custom objects
strtagname = "brazil"
and brazil is definitely a tag name stored within one of the custom objects in the array.
However the function continually returns false.
Can someone confirm to me that the above should or should not work.
and if it wont work can someone tell me the best way to test if any of the objects in the array contain a property with a specific value.
I suppose in summary I am looking for the equivalent of a SQL EXISTS statement.
Many thanks in hope.
Your code is currently checking whether the count is exactly one.
The equivalent of EXISTS in LINQ is Any. You want something like:
Return DataCache.Tags.Any(Function(tag) tag.FldTag = strtagname)
(Miraculously it looks like that syntax may be about right... it looks like the docs examples...)
Many Thanks for the response.
Your code did not work. Then I realised that I was comparing to an array value so it would be case sensitive.
However glad I asked the question, as I found a better way than mine.
Many thanks again !