我需要在特定条件下查找数组中的重复行

Question

我有一个帐户列表，需要找到具有特定条件的重复行，并且当存在多于一个条件的行时显示错误。

1. 相同的编号和描述
2. 相同编号的不同描述
3. 数字为空，描述相同。

4. 不同的编号和相同的描述＃`

   const accounts = [
           { id: 1, number: '1', description: 'desc1' },
           { id: 2, number: '2',  description: 'desc2' },
           { id: 3, number: null, description: null },
           { id: 4, number: '1', description: 'desc1' },
           { id: 5, number: '1', description: 'desc3' },
           { id: 6, number: '1', description: 'desc4' },
           { id: 7, number: null, description: 'desc5' },
           { id: 8, number: null, description: 'desc5' }
         ];
       findDuplicates(accounts) {
         const duplicates = accounts
           .map((account) => {
             return {
               count: 1,
               number: account.number,
               description: account.description
             };
           })
         .reduce((arr, row) => {
           // try to find the current row in count array
           const existingRow = arr.find((countRow) => {
             return (countRow.number === row.number && countRow.description === row.description);
           });
           if (existingRow !== undefined) {
             existingRow.count += 1;
           } else { // otherwise, push it onto the count array
             arr.push(row);
           }`enter code here`
           return arr;
         }, []).filter((duplicateRows) => {
           return duplicateRows.count > 1; // filter the list down to only accounts with more than 1 account
         });
         return duplicates;
   

Answer 1

这个简单的生成器函数技巧可以使您重复

const accounts = [
        { id: 1, number: '1', description: 'desc1' },
        { id: 2, number: '2',  description: 'desc2' },
        { id: 3, number: null, description: null },
        { id: 4, number: '1', description: 'desc1' },
        { id: 5, number: '1', description: 'desc3' },
        { id: 6, number: '1', description: 'desc4' },
        { id: 7, number: null, description: 'desc5' },
        { id: 8, number: null, description: 'desc5' }
      ];

function *findDuplicates(accounts) {
  let bucket = [];
  
  for(let account of accounts) {
    const item = bucket.find(pr => pr.number === account.number 
      && pr.description === account.description);
    
    if(!item) {
      bucket = [...bucket, account];
      continue;
    }
    
    yield account;
  }
}

console.log([...findDuplicates(accounts)])