How to combine an array of objects into one object and if the value is different then change the val-CodePudding

I want to combine these into one but if the values of the property is different I want to write 'Multiple' instead. Same as you would in a text editor in Pages on Mac.

const myObj = [{
  color: 'Blue',
  font: 'Arial'
},
{
  color: 'Green',
  font: 'Arial'
},
{
  color: 'Blue',
  font: 'Arial'
},]

to be:


const results = {
color: 'Multiple',
font: 'Arial'
}

const results = arrObj.reduce(function(result, currentObject) {
    for (var key in currentObject) {
        if (currentObject.hasOwnProperty(key)) {
            result[key] = currentObject[key]; 
        }
    }
    return result;
}, {});

result is:

{ color: 'Blue', font: 'Arial' }

CodePudding user response：

I don't know if I'd use reduce() in this case. Incrementally building the result object would allow you to easily track values you've already encountered:

const myObj = [{
    color: 'Blue',
    font: 'Arial'
  },
  {
    color: 'Green',
    font: 'Arial'
  },
  {
    color: 'Blue',
    font: 'Arial'
  }
];

function combine(objArray) {
  let result = {};

  for (const obj of objArray) {
    for (const [key, val] of Object.entries(obj)) {
        if (key in result && result[key] !== val) {
          result[key] = "Multiple";
        } else {
          result[key] = val;
        }
      }
    }

    return result;
  }

  console.log(combine(myObj));

CodePudding user response：

Just a port of @Brandon's to using reduce:

function combine(objArray) {
  return objArray.reduce((result, obj) => {
      for (const [key, val] of Object.entries(obj))
          if (key in result && result[key] !== val)
              result[key] = "Multiple";
          else
              result[key] = val;
      return result;
  }, {});
}

console.log(combine([{
  color: 'Blue',
  font: 'Arial'
},
{
  color: 'Green',
  font: 'Arial'
},
{
  color: 'Blue',
  font: 'Arial'
}]));