Objective C tip?

I want to replace this:

self.fajerImage     = [UIImage imageNamed:@"FirstViewBG_5N.png"];
self.shrogImage     = [UIImage imageNamed:@"FirstViewBG_4N.png"];
self.dohorImage     = [UIImage imageNamed:@"FirstViewBG_3N.png"];
self.aaserImage     = [UIImage imageNamed:@"FirstViewBG_2N.png"];
self.mgribImage     = [UIImage imageNamed:@"FirstViewBG_1N.png"];
self.eeshaImage     = [UIImage imageNamed:@"F开发者_如何学编程irstViewBG_0N.png"];

With a for loop.. I don't know how to call the ivars one after another in a loop..

Please note that putting them in an array before the loop is a great idea that I have not been successful in implementing..

Thanks!

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One great way to do this involves key value coding, as discussed in this blog post. Try using:

NSArray *nameArray = [[NSArray alloc] initWithObjects:@"fajerImage",
                                                     @"shrogImage",
                                                     @"dohorImage",
                                                     @"aaserImage",
                                                     @"mgribImage",
                                                     @"eeshaImage",
                                                     nil];

int i = 0;
for (NSString *name in nameArray) {
    UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"FirstViewBG_%dN.png", i++]];
    [self setValue:image forKey:name];
}

[nameArray release];

(You should replace UIImage in my code above with the actual object type, if I've gotten it wrong.)

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You could use Key Value Coding syntax:

NSString *names=[NSArray arrayWithObjects:@"eeshaImage",@"mgribImage",@"aaserImage",@"dohorImage",...,nil];

for (int i=0; i<names.count; i++) {
      NSString *name=[names objectAtIndex:i];
      UIImage *image=[UIImage imageNamed:[NSString stringWithFormat:@"FirstViewBG_%dN.png",i
      [self setValue:image forKey:name];
 }

---

A coworker of mine is fond of a pattern like the following (untested):

 id *images[] = {
    &eeshaImage,
    &mgribImage,
    &aaserImage,
    &dohorImage,
    &shrogImage,
    &fajerImage
 };

 for (size_t i = 0;i < sizeof(images) / sizeof(*images);++i) {
    NSString *name = [NSString stringWithFormat:@"FirstViewBG_%zuN.png", i];
    *(images[i]) = [[UIImage imageNamed:name] retain];
 }

You have to ask yourself if the cost in readability is worth it just to make it a tiny bit more extensible, though.

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Another thing you can do that is usually fast enough is allocate your images on demand rather than try and initialize them all at once. Name them something like "FirstViewBG_Fajer.png" and then write an instance method like:

- (UIImage *) imageNamed:(NSString *) name {
    return [UIImage imageNamed: [NSString stringWithFormat:
    @"FirstViewBG_%@.png", name]];
}