Javascript：添加除数组中的元素之外的所有元素

Question

I have an array of column indexes that looks like, for example, [2, 4, 5] and an object with string value keys ranging from "0" through "6".

I want to create a new array containing all elements from my original object except those with keys matching any value in my column index array. This is how I'm doing it currently but I'm not happy with it:

const convertObjectToArray = (columnIndexes, rowObject) => {
    return Object.keys(rowObject).map(key => {
        let rowValue = '';
        if (columnIndexes.indexOf(parseInt(key)) === -1) {
            rowValue = rowObject['' + key];
        }
        return rowValue;
    });
};

Perhaps there is a very simple, straightforward way of doing this and I'm just missing it?

Answer 1

const convertObjectToArray = (columnIndexes, rowObject) =>
  Object.keys(rowObject)
   .filter( key => columnIndexes.includes(+key))
   .map(key => rowObject[key])

Or if you really want empty strings:

const convertObjectToArray = (columnIndexes, rowObject) =>
  Object.entries(rowObject)
   .map(([key, value]) =>
     columnIndexes.includes(+key)
     ?value
     :""
   );

Answer 2

Here's a solution very close to what you were working with:

const convertObjectToArray = (columnIndexes, rowObject) => {
    return Object.keys(rowObject).map(key => {
        let rowValue = '';
        if (columnIndexes.indexOf(key) === -1) {
            rowValue = rowObject[key];
        } 
        return rowValue;        
    });
};

Answer 3

A straightforward way is to reorganize your code to build the result array directly while looping over the rowObject :

function convertObjectToArray(columnIndexes, rowObject) {
  let res = [];
  for(let key in rowObject)
    if(columnIndexes.indexOf(+key) < 0)
      res.push(rowObject[key]);
  return res;
}

Working demo code in the snippet below:

 let excludeColumns = [2, 4, 5]; let rowObject= { '0': 'value 0', '1': 'value 1', '2': 'value 2', '3': 'value 3', '4': 'value 4', '5': 'value 5', '6': 'value 6' }; console.log( convertObjectToArray(excludeColumns, rowObject) ); function convertObjectToArray(columnIndexes, rowObject) { let res = []; for(let key in rowObject) if(columnIndexes.indexOf(+key) < 0) res.push(rowObject[key]); return res; }