我正在尝试搜索一个"国家名称"；大写和小写。它目前只适用于大写字母，例如："；USA"柬埔寨"。toLowerCase()是一个选项吗？我试过了，但没用。我可能用错了。非常感谢。
我的代码：
const filterCountries = results.filter((item) => {
return searchCountries !== ""
? item.country.includes(searchCountries)
: item;
});
如果您试图根据searchTerm搜索国家/地区，则可以尝试以下操作：
const filterCountries = results.filter((item) => {
return item.country.toLowerCase().includes(searchCountries.toLowerCase())
});
示例：
const countryList = [
"Afghanistan",
"Albania",
"Algeria",
"American Samoa",
"Andorra",
"Angola",
"Anguilla",
"Antarctica",
"Antigua and Barbuda",
"Argentina",
"Armenia",
"Aruba",
"Australia",
"Austria",
"Azerbaijan",
"Bahamas (the)",
"Bahrain",
"Bangladesh",
"Barbados",
"Belarus",
"Belgium",
"Belize",
"Benin",
"Bermuda",
"Bhutan",
"Bolivia (Plurinational State of)",
"Bonaire, Sint Eustatius and Saba",
"Bosnia and Herzegovina",
"Botswana",
"Bouvet Island",
"Brazil",
"British Indian Ocean Territory (the)",
"Brunei Darussalam",
"Bulgaria",
"Burkina Faso",
"Burundi",
"Cabo Verde",
"Cambodia",
"Cameroon",
"Canada",
"Cayman Islands (the)",
"Central African Republic (the)",
"Chad",
"Chile",
"China",
"Christmas Island",
"Cocos (Keeling) Islands (the)",
"Colombia",
"Comoros (the)",
"Congo (the Democratic Republic of the)",
"Congo (the)",
"Cook Islands (the)",
"Costa Rica",
"Croatia",
"Cuba",
"Curaçao",
"Cyprus",
"Czechia",
"Côte d'Ivoire",
"Denmark",
"Djibouti",
"Dominica",
"Dominican Republic (the)",
"Ecuador",
"Egypt",
"El Salvador",
"Equatorial Guinea",
"Eritrea",
"Estonia",
"Eswatini",
"Ethiopia",
"Falkland Islands (the) [Malvinas]",
"Faroe Islands (the)",
"Fiji",
"Finland",
"France",
"French Guiana",
"French Polynesia",
"French Southern Territories (the)",
"Gabon",
"Gambia (the)",
"Georgia",
"Germany",
"Ghana",
"Gibraltar",
"Greece",
"Greenland",
"Grenada",
"Guadeloupe",
"Guam",
"Guatemala",
"Guernsey",
"Guinea",
"Guinea-Bissau",
"Guyana",
"Haiti",
"Heard Island and McDonald Islands",
"Holy See (the)",
"Honduras",
"Hong Kong",
"Hungary",
"Iceland",
"India",
"Indonesia",
"Iran (Islamic Republic of)",
"Iraq",
"Ireland",
"Isle of Man",
"Israel",
"Italy",
"Jamaica",
"Japan",
"Jersey",
"Jordan",
"Kazakhstan",
"Kenya",
"Kiribati",
"Korea (the Democratic People's Republic of)",
"Korea (the Republic of)",
"Kuwait",
"Kyrgyzstan",
"Lao People's Democratic Republic (the)",
"Latvia",
"Lebanon",
"Lesotho",
"Liberia",
"Libya",
"Liechtenstein",
"Lithuania",
"Luxembourg",
"Macao",
"Madagascar",
"Malawi",
"Malaysia",
"Maldives",
"Mali",
"Malta",
"Marshall Islands (the)",
"Martinique",
"Mauritania",
"Mauritius",
"Mayotte",
"Mexico",
"Micronesia (Federated States of)",
"Moldova (the Republic of)",
"Monaco",
"Mongolia",
"Montenegro",
"Montserrat",
"Morocco",
"Mozambique",
"Myanmar",
"Namibia",
"Nauru",
"Nepal",
"Netherlands (the)",
"New Caledonia",
"New Zealand",
"Nicaragua",
"Niger (the)",
"Nigeria",
"Niue",
"Norfolk Island",
"Northern Mariana Islands (the)",
"Norway",
"Oman",
"Pakistan",
"Palau",
"Palestine, State of",
"Panama",
"Papua New Guinea",
"Paraguay",
"Peru",
"Philippines (the)",
"Pitcairn",
"Poland",
"Portugal",
"Puerto Rico",
"Qatar",
"Republic of North Macedonia",
"Romania",
"Russian Federation (the)",
"Rwanda",
"Réunion",
"Saint Barthélemy",
"Saint Helena, Ascension and Tristan da Cunha",
"Saint Kitts and Nevis",
"Saint Lucia",
"Saint Martin (French part)",
"Saint Pierre and Miquelon",
"Saint Vincent and the Grenadines",
"Samoa",
"San Marino",
"Sao Tome and Principe",
"Saudi Arabia",
"Senegal",
"Serbia",
"Seychelles",
"Sierra Leone",
"Singapore",
"Sint Maarten (Dutch part)",
"Slovakia",
"Slovenia",
"Solomon Islands",
"Somalia",
"South Africa",
"South Georgia and the South Sandwich Islands",
"South Sudan",
"Spain",
"Sri Lanka",
"Sudan (the)",
"Suriname",
"Svalbard and Jan Mayen",
"Sweden",
"Switzerland",
"Syrian Arab Republic",
"Taiwan",
"Tajikistan",
"Tanzania, United Republic of",
"Thailand",
"Timor-Leste",
"Togo",
"Tokelau",
"Tonga",
"Trinidad and Tobago",
"Tunisia",
"Turkey",
"Turkmenistan",
"Turks and Caicos Islands (the)",
"Tuvalu",
"Uganda",
"Ukraine",
"United Arab Emirates (the)",
"United Kingdom of Great Britain and Northern Ireland (the)",
"United States Minor Outlying Islands (the)",
"United States of America (the)",
"Uruguay",
"Uzbekistan",
"Vanuatu",
"Venezuela (Bolivarian Republic of)",
"Viet Nam",
"Virgin Islands (British)",
"Virgin Islands (U.S.)",
"Wallis and Futuna",
"Western Sahara",
"Yemen",
"Zambia",
"Zimbabwe",
"Åland Islands"
];
let searchCountries = "India";
const filterCountries = countryList.filter((item) => {
return item.toLowerCase().includes(searchCountries.toLowerCase())
});
console.log(filterCountries)如果您试图进行不区分大小写的搜索/筛选，则应忽略两个术语的大小写，或者换句话说，使它们之间的大小写相同。筛选数组意味着筛选器回调应该为正在筛选的当前元素返回true/false。如果搜索项为false，则返回true以允许元素通过。
const filterCountries = results.filter(({ country }) => {
const searchTerm = searchCountries.toLowerCase();
return searchTerm
? country.toLowerCase().includes(searchTerm)
: true;
});
有趣的是，所有字符串都包括子字符串""，因此检查搜索项是否为truthy/falsy是不相关的。您可以简单地检查它是否包含在国家/地区字符串中。
const filterCountries = results.filter(({ country }) => {
const searchTerm = searchCountries.toLowerCase();
return country.toLowerCase().includes(searchTerm);
});