從具有不同鍵的數組中按值刪除項目

Question

我正在嘗試創建一個從我的 JSON 文件中刪除一個單詞的函數。

功能：

function removeword(lang,word) {

  var farr = [];
  var count = 0;

  fs.readFile('./dictionary.json', 'utf8', (err, jsonString) => {
    var items = JSON.parse(jsonString);

    for (var i = 0; i < items.length; i++) {
      console.log(items[lang][i]);
      if (word === items[lang][i]) {
        items[lang].splice(i, 1);
      }
    }

    console.log(items);

     fs.writeFile("./dictionary.json", JSON.stringify(items), function(err){
           if (err) throw err;
           console.log('Done!');
     });

  });
}

原始 JSON：

{"en":["moon","crazy"],"pt":["macaco", "macarrão"],"es":["hola"]}

通過調用 removeword('pt', 'macaco')，這是我的期望：

{"en":["moon","crazy"],"pt":["macarrão"],"es":["hola"]}

Answer 1

您可以為給定的鍵在您的items數組上調用.filter() ，您可以通過。 對於數組中不是您的值的任何元素，您可以通過返回true ( v !== value ) 來保留它，否則，您可以刪除它（通過返回 false）：

 const items = {"en":["moon","crazy"],"pt":["macaco", "macarrão"],"es":["hola"]}; function removeword(obj, key, value) { obj[key] = obj[key].filter(v => v !== value); } removeword(items, 'pt', 'macaco'); console.log(items); // {"en":["moon","crazy"],"pt":["macarrão"],"es":["hola"]}

如果您不想修改您的items數組（而是返回一個新的修改過的items數組），您可以使用Object.fromEntries()從[key, value]對數組創建一個新對象，您可以在其中過濾value數組，如果key匹配您傳入的鍵：

 const items = {"en":["moon","crazy"],"pt":["macaco", "macarrão"],"es":["hola"]}; const removeword = (obj, key, value) => Object.fromEntries( Object.entries(obj).map(([k, arr]) => k === key ? [k, arr.filter(v => v !== value)] : [k, arr]) ); const result = removeword(items, 'pt', 'macaco'); console.log(result); // {"en":["moon","crazy"],"pt":["macarrão"],"es":["hola"]}

^{請參閱Object.fromEntries() 瀏覽器兼容性}

上面不可變方法的瀏覽器兼容版本會使用.reduce() ：

 const items = {"en":["moon","crazy"],"pt":["macaco", "macarrão"],"es":["hola"]}; const removeword = (obj, key, value) => Object.keys(obj).reduce((o, k) => ({...o, [k]: k === key ? obj[k].filter(v => v !== value) : obj[k]}), {}) const result = removeword(items, 'pt', 'macaco'); console.log(result); // {"en":["moon","crazy"],"pt":["macarrão"],"es":["hola"]}