I have an object Student with 4 attributes(age,name,department,surname). and I create an array of that object like this;
Student students[10] blah blah init blah.
then i want to use an Student array as argument for a method;
-(void) displayStudentInArray : (????) studentarray atIndex: (int) index {.....}
'???' are my problem. what do i write there? i ve no idea.
need help. i m new on objective c.
Rather than using C notation the array should be made like this:
NSArray *studentArray = [[NSArray alloc] initWithObjects: student1, student2, student2, ..., nil];
In which case the parameter type will be NSArray
-(void) displayStudentInArray : (NSArray *)studentarray atIndex: (int) index {.....}
Student studentTwo = [studentArray objectAtIndex:1]; or in general Student chosenStudent = [studentArray objectAtIndex:index]; also, in the new SDK's you may use studentArray[index]-(void) displayStudentInArray:(Student **) studentarray.... then i get bad access on next line in that method Student *studentTwo = studentarray[index]; ??The preferred method for creating arrays is using NSArray (or NSMutableArray if you want to modify the array after it is created):
NSArray *array = [[NSArray alloc]initWithObjects:student1, student2...];
Then your method signature would be:
-(void)displayStudentInArray:(NSArray *)studentarray atIndex:(int)index
These answers are correct, but if you really want to use C notation, you just need to add another asterisk to denote a reference to another pointer:
- (void)displayStudentInArray:(Student**)studentArray atIndex:(int)index {
Student* firstStudent = studentArray[1];
//do what you want with the array
}
This is because C arrays are really just pointers to an address in memory. If you wanted a C array for a primitive, it would look like this:
int* arrayOfInts = malloc(yourSize * sizeof(int));
You have an array of objects, but the idea is just the same. You just add one more asterisk to denote that it's a pointer to a pointer to an object.
Student** students = ...
Just write
Student *tempStudent = (array)[0];
