Hey guys,
So I am busy reading an objective-c book by Big Nerd Ranch. I'm on chapter 17 at the moment and managed to complete the required challenge at the end of the chapter. However, I just have two question that I would like to understand.
In the following bit of code - StockHolding is a custom class that has instance variables and the stocks (an array) points to three instances of stockholding with values setting its stock value and cost in dollars.
At first I tried to access the array to get the data from the objects it pointed to - but it seems that was not going to work as the array doesn't know what data its objects contain - just where they are in memory, right?
What I want to know is why was it necessary to create a new instance of stockholding (holdings) in this for loop to access those variables?
How does the new instance of stockholding know what the values of my stocks are?
I'm going to try have a guess here to see if maybe I understand it a little better?
We create an instance of our class in the for loop so that we have access to its instance methods and variables - then we use the stocks array to get the variables from those objects in the array?
I may be completely off..
Any advice?
Thanks guys!
So I am busy reading an objective-c book by Big Nerd Ranch. I'm on chapter 17 at the moment and managed to complete the required challenge at the end of the chapter. However, I just have two question that I would like to understand.
In the following bit of code - StockHolding is a custom class that has instance variables and the stocks (an array) points to three instances of stockholding with values setting its stock value and cost in dollars.
At first I tried to access the array to get the data from the objects it pointed to - but it seems that was not going to work as the array doesn't know what data its objects contain - just where they are in memory, right?
What I want to know is why was it necessary to create a new instance of stockholding (holdings) in this for loop to access those variables?
How does the new instance of stockholding know what the values of my stocks are?
Code:
for (StockHolding *holdings in stocks){
NSLog (@ "%@ has %d shares. Cost: $%.2f. Stock value: $%.2f", [holdings stockName],
[holdings numberOfShares],
[holdings costInDollars],
[holdings valueInDollars]);
}
I'm going to try have a guess here to see if maybe I understand it a little better?
We create an instance of our class in the for loop so that we have access to its instance methods and variables - then we use the stocks array to get the variables from those objects in the array?
I may be completely off..
Any advice?
Thanks guys!