Question

I have an object that returns a value if successful and false (or nil) if it failed.

i want to assign that value to a variable

if(var1 = [object foo])
{
    //if the [object foo] returned a variable, goes here
}
else
{
    //[object foo] returned FALSE (or nil), go here
}

can an If statement detected if an assignment was valid?

Answer 1

Not sure I understand your question, but let me try and explain a few situations you can check

1) Property contains value

if ([object foo])
{
    // If foo has a value associated to it that is not nil/false/zero
}
else
{
    // If foo equals nil, false or zero
}

2) Assignment to a variable was successful

if ((bar = [object myMethod]))
{
    // If myMethod returns any non-nil value
}
else
{
    // If myMethod returns nil
}

3) Previous assignment of a variable was successful

bar = [object myMethod];

if (bar)
{
    // If bar has a value associated to it that is not nil/false/zero
}
else
{
    // If bar equals nil, false or zero
}