Question

我正在寻找一种方法来访问“健康”和“健康”。和＆＃39; gif＆＃39;我的对象内的键。现在，我只能在页面上显示一个或另一个 - ＆＃39; fit＆＃39;作为一个形象和＆＃39; gif＆＃39;是一个GIF。

我想我可能会使用.match，但我并不确定正确的语法

由于

const sizeMappings = {
master: '1280',
  small: '192w',
  small_fit: '192w',
  medium: '384w',
  medium_low_res: '288w',
  medium_fit: '384w',
  medium_gif: '384w',
  medium_fit_low_res: '288w',
  large: '768w',
  large_fit: '768w',
  large_gif: '768w',
  xlarge: '1280w',
  xlarge_fit: '1280w',
}

const getSrcSet = (renditions, fit, gif) => {
  const sizes = Object.keys(sizeMappings)
    .map((key) => {
      if (fit && !key.includes('fit')) return null
      const mapping = `${renditions[key]} ${sizeMappings[key]}`
      return mapping
    })

  return sizes
    .filter(el => el !== null)
    .join(',')
}

Answer 1

我会使用filter()而不是map()，因为您实际上想要提取数组的子集。然后，只需将每个键匹配为给定的大小名称+ "_gif"或大小名称+ "_fit"。

＆＃13;

const sizeMappings = {
  master: '1280',
  small: '192w',
  small_fit: '192w',
  medium: '384w',
  medium_low_res: '288w',
  medium_fit: '384w',
  medium_gif: '384w',
  medium_fit_low_res: '288w',
  large: '768w',
  large_fit: '768w',
  large_gif: '768w',
  xlarge: '1280w',
  xlarge_fit: '1280w',
}

let size = "large";  //change me

let arr = Object.keys(sizeMappings).filter(
  (key) => (key === size + "_fit" || key === size + "_gif")
);

console.log(arr)

＆＃13;

Answer 2

首先过滤然后根据需要映射结果：

const getSrcSet = (renditions, fit, gif) => {
  return Object.keys(sizeMappings)
    .filter(key => fit && key.includes('fit') || gif && key.includes('gif'))
    .map(key => `${renditions[key]} ${sizeMappings[key]}`)
    .join(',')
  }

多个＆＃39;包括＆＃39;在函数

2 个答案: