如何在邮递员中使用JavaScript向JSON数组添加唯一对象

Question

I am trying to add json object to json array, but seems something wrong. what I'm getting array elements as -

0:{}
    local:"con"
    name:"con"
    order:15
1:{}
    local:"con"
    name:"con"
    order:15

what I'm expecting to happen -

0:{}
    local:"con"
    name:"con"
    order:15
1:{}
    local:"con2"
    name:"con2"
    order:16

I want points array should have all unique json objects(with very for loop iteration) but it replaces all previously added json with current json(of current iteration) object and entire array has same json objects at all index positions
code -

for(var i = 0; i < machineDetails.length; i++)
{

          machine['name'] = machineDetails[i].name;
          machine['local'] = machineDetails[i].localName;
          machine['order'] = machineDetails[i].orderInLine;
          points.push(machine);
          console.log(points);
}

in addition to above I tried points[i].push(machine); but it does not work either and throws error as push property is not defined . Please point me in right direction what i am missing or what should I do?

Answer 1

You need to move an assignment of an empty object inside of the loop, to prevent the same object reference, which leads to same values inside.

for (var i = 0; i < machineDetails.length; i++) {
    machine = {};

or even shorter:

for (var i = 0; i < machineDetails.length; i++) {
    points.push({
        name: machineDetails[i].name,
        local: machineDetails[i].localName,
        order: machineDetails[i].orderInLine
    });
}

Answer 2

When using arrays you can use different types of iterations including array.map which seems to be exactly what you are doing: Mapping the array called machineDetails to a new one called points :

const points = machineDetails.map(({ name, localName, orderInLine}) => ({
  name,
  local: localName,
  order: orderInLine,
});

Using map since you are creating a new scope and returning a new object every time the issue in hand which is overriding attributes of an object which you have already referenced it into your array is not going to happen.