Accesing a method for a object in an array

[Anders hofel]

Hi fellas,

All new to objective c, and i have some problems with the following simple code.


int i = 0;
for(Item *q in array){
valueInDollars += [array objectAtIndex:i "getValueInDollars"];
i++;
}

The "getValueInDollars" is how i want it to work - i obviously have a getValueInDollars method in my Item class, but i don't know the correct syntactic way to access it.

In java it would be something like array[i].getValueInDollars....

i hope its clear what I'm trying to achieve.

[Bernhard Haeussermann]

Hi Anders,

the syntax for calling a method having no parameters on an object in Objective-C is as follows:

[myObject myMethod]

The syntax for calling a method with a number of parameters is:

[myObject myMethodParam1:paramValue1 param2:paramValue2 param3:paramValue3]

In this example the name of the method is myMethodParam1:param2:param3: (each ':' acts as a placeholder for a parameter) and paramValue1, paramValue2, and paramValue3 are names of variables.

In Objective-C, each pair of square brackets delimit one method call. In your example there are two method calls: one to the objectAtIndex: method and one to the getValueInDollars method - thus you need two pairs of square brackets, like this:

valueInDollars+=[[array objectAtIndex:i] getValueInDollars];

I found a good basic tutorial about Objective-C here on Cocoa Dev Central. I recommend you work through it - it will make your life much easier.