Iterating Arrays in Objective-C

Objective-C provides several mechanisms for iterating through an array. One can

1. Iterate the array by index
2. Use an iterator to walk the array
3. Use the for in syntax

The dummy program below illustrates these methods.

If you are working from the command-line instead of from Xcode, the compilation line is

gcc -framework Foundation array.m -o array

array.m

---

#include <stdlib.h>

#import <Foundation/Foundation.h>

static void printArray1(NSArray *array)
{
    size_t i = 0;
    size_t length = [array count];
    for (i = 0; i < length; i++) {
        NSLog(@"%@", [array objectAtIndex: i]);
    }
}

static void printArray2(NSArray *array)
{
    NSEnumerator *enumerator = [array objectEnumerator];
    id object;
    while ((object = [enumerator nextObject]) != nil) {
        NSLog(@"%@", object);
    }
}

static void printArray3(NSArray *array)
{
    for (id object in array) {
        NSLog(@"%@", object);
    }
}

int main(int argc, const char *argv[])
{
    int i;
    NSMutableArray *numbers;
    NSArray *sorted;
    numbers = [[NSMutableArray alloc] init];

    for (i = 1; i < argc; i++) {
        [numbers addObject:[NSNumber numberWithInt:atoi(argv[i])]];
    }

    NSLog(@"----------PRINT1----------------");
    printArray1(numbers);
    NSLog(@"----------PRINT2----------------");
    printArray2(numbers);
    NSLog(@"----------PRINT3----------------");
    printArray3(numbers);
    return 0;
}