merge array with unique keys

Question

I have array of objects called newArray and oldArray.

Like this : [{name: 'abc', label: 'abclabel', values: [1,2,3,4,5]}]

example : 
newArray = [
{name: 'abc', label: 'abclabel', values: [1,2,3,4,5]}, 
{name: 'test', label: 'testlabel', values: [1,2,3,4]}
]

oldArray = [
{name: 'oldArray', label: 'oldArrayLabel', values: [1,2,3,4,5]}, 
{name: 'test', label: 'testlabel', values: [1,2,3,4,5]}
]

result will be = [
{name: 'abc', label: 'abclabel', values: [1,2,3,4,5]}, 
{name: 'test', label: 'testlabel', values: [1,2,3,4]}, 
{name: 'oldArray', label: 'oldArrayLabel', values: [1,2,3,4,5]}
];

I wanted to merge both the array in such a way that whenever name and label are equal in both the arrays it should only consider newArray value.

I have tried

function mergeArrayWithLatestData (newData, oldData) {
  let arr = [];
  let i = 0; let j =0
  while ((i < newData.length) && (j < oldData.length)) {
    if ((findIndex(newData, { name: oldData[i].name, label: oldData[i].label })) !== -1) {
      arr.push(newData[i])
  } else {
    arr.push(newData[i]);
    arr.push(oldData[i]);
  }
  i += 1;
  j += 1;
}
while (i < newData.length) {
    arr.push(newData[i]);
 }
 return arr;
}

But i am not getting correct result.

Any suggestions?

Answer 1

You could add all array with a check if name/label pairs have been inserted before with a Set.

var newArray = [{ name: 'abc', label: 'abclabel', values: [1, 2, 3, 4, 5] }, { name: 'test', label: 'testlabel', values: [1, 2, 3, 4] }],
    oldArray = [{ name: 'oldArray', label: 'oldArrayLabel', values: [1, 2, 3, 4, 5] }, { name: 'test', label: 'testlabel', values: [1, 2, 3, 4, 5] }],
    result = [newArray, oldArray].reduce((s => (r, a) => {
        a.forEach(o => {
            var key = [o.name, o.label].join('|');
            if (!s.has(key)) {
                r.push(o);
                s.add(key);
            }
        });
        return r;
    })(new Set), []);

console.log(result);

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