ios - 使用 NSPredicate 比较两个数组

Question

我有两个数组，一个代表全尺寸图像列表，另一个代表图像的缩略图。有没有办法使用 NSPredicate 检查全尺寸图像是否有缩略图？

缩略图称为 img{number}_thumb.jpg，全尺寸图像称为 img{number}.jpg。

Answer 1

使用数组、字符串和循环:

NSArray *thumbs=@[@"img1_thumb.jpg",@"img2_thumb.jpg",@"img3_thumb.jpg",@"img4_thumb.jpg",@"img5_thumb.jpg",];
NSArray *images=@[@"img1",@"img2",@"img3",@"img41",@"img5"];

BOOL isSame=YES;
for (NSString *name in images) {
    if (![thumbs containsObject:[NSString stringWithFormat:@"%@_thumb.jpg",name]]) {
        isSame=NO;
        NSLog(@"%@ doesn't has thumb image",name);
        break; //if first not found is not good enough remove this break
    }
}
NSLog(@"%@",isSame?@"All thumb has image":@"All thumb does not have image");

---

使用 NSPredicate:

for (NSString *image in images) {
    NSPredicate *predicate=[NSPredicate predicateWithFormat:@"SELF like [c]%@",[NSString stringWithFormat:@"%@_thumb.jpg",image]];
    NSArray *filtered=[thumbs filteredArrayUsingPredicate:predicate];
    if (filtered.count==0) {
        NSLog(@"%@ not found",image);
    }
}