NSArray 等效于 Map [英] NSArray Equivalent of Map

问题描述

给定 NSDictionary 对象的 NSArray(包含类似的对象和键)是否可以将执行映射到指定键的数组?例如，在 Ruby 中，它可以通过:

Given an NSArray of NSDictionary objects (containing similar objects and keys) is it possible to write perform a map to an array of specified key? For example, in Ruby it can be done with:

array.map(&:name)

推荐答案

更新:如果您使用的是 Swift，请参阅 地图.

Update: If you're using Swift, see map.

BlocksKit 是一个选项:

NSArray *new = [stringArray bk_map:^id(NSString *obj) { 
    return [obj stringByAppendingString:@".png"]; 
}];

<小时>

Underscore 是另一种选择.有一个 map 函数，这里是一个来自网站的例子:

---

Underscore is another option. There is a map function, here is an example from the website:

NSArray *tweets = Underscore.array(results)
    // Let's make sure that we only operate on NSDictionaries, you never
    // know with these APIs ;-)
    .filter(Underscore.isDictionary)
    // Remove all tweets that are in English
    .reject(^BOOL (NSDictionary *tweet) {
        return [tweet[@"iso_language_code"] isEqualToString:@"en"];
    })
    // Create a simple string representation for every tweet
    .map(^NSString *(NSDictionary *tweet) {
        NSString *name = tweet[@"from_user_name"];
        NSString *text = tweet[@"text"];

        return [NSString stringWithFormat:@"%@: %@", name, text];
    })
    .unwrap;

这篇关于NSArray 等效于 Map的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！