Swift:根据键将字典数组转换为String数组

Question

以下是我的字典数组,我希望得到一个基于特定键的字符串数组(contentURL在我的情况下是键).

我怎样才能实现它？我曾经碰到Reduce&Filter但没有一个适合我的要求.

(
  {
    contentURL = "https://d1shcqlf263trc.cloudfront.net/1510232473240ab.mp4";
  },
  {
    contentURL = "https://d1shcqlf263trc.cloudfront.net/151021804847312.mp4";
  },
  {
    contentURL = "https://d1shcqlf263trc.cloudfront.net/151021536556612.mp4";
  },
  {
    contentURL = "https://d1shcqlf263trc.cloudfront.net/151021528690312.mp4";
  }
)

预期产出

[
  "https://d1shcqlf263trc.cloudfront.net/1510232473240ab.mp4", 
  "https://d1shcqlf263trc.cloudfront.net/151021804847312.mp4",
  "https://d1shcqlf263trc.cloudfront.net/151021536556612.mp4", 
  "https://d1shcqlf263trc.cloudfront.net/151021528690312.mp4"
]

Answer 1

只是用 compactMap

 let array = arrayOfDicts.compactMap {$0["contentURL"] }