使用lodash，你可以使用_.union()和_.spread()来生成一个函数，该函数可以展平为一个具有唯一值的数组：

const fn = _.spread(_.union);

const arrs = [ 
  ["General Fitness", "Health & Fitness"],
  ["Cardiovascular", "Meditation"],
  ["Health & Fitness", "Cardiovascular", "General Fitness"],
  ["Cardiovascular"]
];

const result = fn(arrs);

console.log(result);

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使用ES6，你可以flatten数组，并通过将其传递给Set和spreading返回数组来使结果唯一：

const arrs = [ 
  ["General Fitness", "Health & Fitness"],
  ["Cardiovascular", "Meditation"],
  ["Health & Fitness", "Cardiovascular", "General Fitness"],
  ["Cardiovascular"]
];

const result = [...new Set(arrs.flat())];

console.log(result);

const arrs = [ 
  ["General Fitness", "Health & Fitness"],
  ["Cardiovascular", "Meditation"],
  ["Health & Fitness", "Cardiovascular", "General Fitness"],
  ["Cardiovascular"]
];

const result = _.uniq(_.flatten(arrs));

console.log(result);

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使用工会

var object =  ["General Fitness", "Health & Fitness"];
var other =  ["Cardiovascular", "Health & Fitness", "Meditation"]
 
_.union(object, other);

// ["General Fitness", "Health & Fitness", "Cardiovascular", "Meditation"]

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简单地使用lodash flatten method：

const arrs = [ 
  ["General Fitness", "Health & Fitness"],
  ["Cardiovascular", "Meditation"],
  ["Health & Fitness", "Cardiovascular", "General Fitness"],
  ["Cardiovascular"]
];

result = _.flatten(arrs);

console.log(result);