Objective-C Programming: The Big Nerd Ranch Guide

Iterating over arrays

Programmers often need to loop and perform operations on each item in an array (or “iterate over an array”). You can do this with a for-loop. Edit main.m:

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[])
{
    @autoreleasepool {

        // Create three NSDate objects
        NSDate *now = [NSDate date];
        NSDate *tomorrow = [now dateByAddingTimeInterval:24.0 * 60.0 * 60.0];
        NSDate *yesterday = [now dateByAddingTimeInterval:-24.0 * 60.0 * 60.0];

        // Create an array containing all three
        NSArray *dateList = @[now, tomorrow, yesterday];

        // Print a couple of dates
        NSLog(@"The first date is %@", dateList[0]);
        NSLog(@"The third date is %@", dateList[2]);

        // How many dates are in the array?
        NSLog(@"There are %lu ...