javascript - 通过字符串比较对数组进行排序

Question

var countries = ["Algeria", "Canada", "Danmark", "Estonia"];
var search = "da";

现在我希望对这个列表进行排序，以便得到以下信息：

sortedCountries === [“丹麦”、“加拿大”、“阿尔及利亚”、“爱沙尼亚”]

我希望 DAnmark 出现在 CanaDA 之前，因为在该字符串的前面找到了“da”。我不希望按升序/降序进行排序。

标签： javascriptsortingcomparison

Answer 1

您可以使用Array.prototype.sort：

var countries = ["Algeria", "Canada", "Danmark", "Estonia"];
var search = "da";

console.log(countries.sort((a, b) => {
  a = a.toLowerCase().indexOf(search) + 1
  b = b.toLowerCase().indexOf(search) + 1
  
  if(!a && !b) return 0
  else if(!a) return 1
  else if(!b) return -1
  else return a - b
}))

我们也可以把它写成一个实用函数：

var countries = ["Algeria", "Canada", "Danmark", "Estonia"]

const searchCountries = (a, s) => a.sort((a, b) => {
  s = s.toLowerCase()
  a = a.toLowerCase().indexOf(s) + 1
  b = b.toLowerCase().indexOf(s) + 1
  
  if(!a && !b) return 0 // don't sort if search fails for both
  else if(!a) return 1 // swap results since b has a value, but a doesn't
  else if(!b) return -1 // leave results since a has a value, but b doesn't
  else return a - b // otherwise, sort by indexOf result
})

console.log(searchCountries(countries, 'da'))
console.log(searchCountries(countries, 'a'))
console.log(searchCountries(countries, prompt()))