Thread: nested IFs? works lijke this i want know if i understanded correctly.

I'm not sure if you're specifically asking a question, but yes, your understanding of nested "if"s seems to be correct.

Let's expand your example a bit:

Code:

if (x==0)
{
    if (Function()==ERROR)
    {
        /* this happens */
    }
    else
    {
        printf("Function has performed successfully.\n");
    }
}

So...

If 'x' is zero...
- if the function returns a code called ERROR, the "this happens" part is executed
- else (if the function does not return an error), a "success" message is printed

If 'x' is NOT zero, the function is not even called since the inner code is not executed.

If you want to test your understanding a little more, explain what similarities and differences of behaviour there are between your example and this one.

Code:

if (x == 0 && Function() == ERROR)
{
     /* this happens */
}

While this example doesn't involve nested loops, there is a specific relationship between your example and this, so it is relevant to understand/explain how the expression "x == 0 && Function() == ERROR" is evaluated.

Originally Posted by Vanhapolle

I talked "nested IFs" (maybe incorrect term) not Loops

Yeah, okay. I committed a typo. I used the word "loops" instead of "ifs".

Originally Posted by Vanhapolle

i know && is LOGICAL AND which means both things are true then is this speffic part code is executed but if both or one is false code is not executed,and || is LOGICAL OR where only one thing must be true not both or they are both false. at least i understanded it this way.

There's more to it than that. Look up "short circuit evaluation". It is a property of the binary logical operators (&& and ||) that affects whether some parts of logical expressions are evaluated.

Originally Posted by Vanhapolle

My way is better becouse real world thing going check more than single "Function()" return codes if x=0.

Maybe, maybe not.

There are many different ways of achieving what you seek to do. There is rarely a universal better though .... there are simply different sets of advantages and disadvantages.

By your description, you have demonstrated you only partially understand the logical operators, and the purpose of my suggestion was to encourage you to build a more complete understanding. With a more complete understanding, you might draw a different conclusion.

But with a partial understanding of one alternative, you can hardly claim to be qualified to judge if it is better or worse than your chosen solution. Claiming you have more information, that you are choosing not to provide, does not really change that.

Originally Posted by Vanhapolle

this exact thing in this operating system one functions gives when it fails NULL then another function called IoErr gives number which tells what goed wrong. All other numbers in first thing are pointers for example data if all goed well.

Although you presumably think otherwise, nothing that you describe here invalidates what I've written in this thread.

I suggest, as previously, that you look up "short circuit evaluation" (in the context of C expressions).