javascript - 合并 JavaScript 对象重复项

Question

我想将其余值与 Javascript 对象中的相同键连接起来。 想要使用普通脚本或 lodash 来解决它..

示例:

obj = [
  { M: 'M1', F: '123-test-123', CODE: 'A' },
  { M: 'M1', F: '123-test-123', CODE: 'B' },
  { M: 'M1', F: '123-test-123', CODE: 'C' },
  { M: 'M2', F: '123-test-456', CODE: 'A' },
  { M: 'M2', F: '123-test-456', CODE: 'A' }
  ...
]

期望的结果:

obj = [
  { M: 'M1', F: '123-test-123', CODE: 'A,B,C' },
  { M: 'M2', F: '123-test-456', CODE: 'A,B' },
  ...
]

谢谢!!!

Answer 1

您可以使用Array.reduce()来获得所需的输出:

var obj = [
  { M: 'M1', F: '123-test-123', CODE: 'A' },
  { M: 'M1', F: '123-test-123', CODE: 'B' },
  { M: 'M1', F: '123-test-123', CODE: 'C' },
  { M: 'M2', F: '123-test-456', CODE: 'A' },
  { M: 'M2', F: '123-test-456', CODE: 'A' }
];

var res = obj.reduce((acc, item) => {
  let existItem = acc.find(({M, F}) => M === item.M && F === item.F);
  if(existItem) {
    existItem.CODE += ',' + item.CODE;
  } else {
    acc.push(item);
  }
  return acc;
}, []);

console.log(res);

除此之外使用另一种方式，Array.reduce():

var obj = [
  { M: 'M1', F: '123-test-123', CODE: 'A' },
  { M: 'M1', F: '123-test-123', CODE: 'B' },
  { M: 'M1', F: '123-test-123', CODE: 'C' },
  { M: 'M2', F: '123-test-456', CODE: 'A' },
  { M: 'M2', F: '123-test-456', CODE: 'A' }
];

var resObj = {};

obj.forEach((item) => {
  let settingValues = resObj[item.M] ? 
    resObj[item.M].CODE += ',' + item.CODE :
    resObj[item.M] = item;
});

console.log(Object.values(resObj));