Javascript 使用LocaleCompare()进行排序时，首先使用大写字母

发布于03月20日

我想用字符串对数组排序.但是，大写字母应该总是在相应的小写字母之前(例如顺序:A a B b...).

为了存档，我try 使用localCompare与caseFirst: "upper"和sensitivity: "case":

const input = ["ADR 2023", "Added Values", "DEMO build", "DEMO Build", "2nd Outlook", "demo award"]
const output = input.sort((a, b) => a.localeCompare(b, "en-US", { caseFirst: "upper", sensitivity: "case" }))
console.log(output)

我希望输出是:

["2nd Outlook", "ADR 2023", "Added Values", "DEMO Build", "DEMO build", "demo award"]

不幸的是，输出是:

["2nd Outlook", "Added Values", "ADR 2023", "demo award", "DEMO Build", "DEMO build"]

如何获得预期订单？在这个例子中，我使用了en-US作为locale.然而，在我的实际项目中，它可以是任何支持的语言环境，长度为五个字符.

推荐答案

不要使用localeCompare)，因为它每次都产生Intl.Collator—太慢了.
您可以逐个字符比较，以确保可以处理任意数量的大写字母.

const input = ["ADR 2023", "Added Values", "DEMO build", "DEMO Build", "2nd Outlook", "demo award"];
const {compare} = Intl.Collator("en-US", { caseFirst: "upper"});
const output = input.sort((a, b) => {
  for(let i = 0; i < a.length && i < b.length; i++){
    const r = compare(a[i], b[i]);
    if(r) return r;
  }
  if(a.length > b.length) return 1;
  if(a.length < b.length) return -1;
  return 0;
})
console.log(output)

VLAZ建议的字符串迭代器版本:

const input = ["ADR 2023", "Added Values", "DEMO build", "DEMO Build", "2nd Outlook", "demo award"];
const {compare} = Intl.Collator("en-US", { caseFirst: "upper"});
const output = input.sort((a, b) => {
  const ia = a[Symbol.iterator](), ib = b[Symbol.iterator]();
  while(true){
    const ca = ia.next().value, cb = ib.next().value;
    if(!ca) return ba ? -1 : 0
    if(ca && !cb) return 1;
    const r = compare(ca, cb);
    if(r) return r;
  }
})
console.log(output)