如何遍历对象数组以添加缺失值的对象

Question

I have a bar chart with data filtered by week (Sun-Sat). However, when a "day" is missing I get an empty space in the graph and I would like to fill that day with the value of "0".

Code and data:

const data = [{value: 2, createdDate: "20201025", day: "Sun" }, {value: 7, createdDate: "20201027", day: "Tue", {value: 5, createdDate: "20201028", day: "Wed"}];

const startOfWeek = moment().startOf('isoWeek');
const endOfWeek = moment().endOf('isoWeek');
const currentWeek = data.filter((e) => moment(e.date) >= startOfWeek && moment(e.date) <= endOfWeek);

How do I add Mon, Thu, Fri, and Sat with values of 0 to the currentWeek array?

Answer 1

Make an array of weekdays you want to test:

const weekdays = ['Sun','Mon','Tue','Wed','Thu','Fri','Sat'];

Loop through them, adding a "zero" event to currentWeek whenever it doesn't contain that weekday:

weekdays.forEach( function(weekday) {
  let found = false; // assume
  for ( var i=0; i < currentWeek.length; i++ ) {
     if ( currentWeek[i].day == weekday ) {
        found = true;
        break;
     }
  }

  // weekday isn't in currentWeek, so add it:
  if ( ! found ) {
     currentWeek = currentWeek.concat( { value: 0, day: weekday } );
  }
} );

Answer 2

Actually I think you could think it from another perspective.
First you fake an array of each day like below:

{value: 0, createdDate: "20201001", day: "Sun" }

After that you can merge two array together.

Answer 3

If the order of your days in the array doesn't matter, this is how I would do it:

// create an array of short weekdays from moment
const weekdays = moment.weekdaysShort();

// iterate over the days
for (const day of weekdays) {

  // check if this day does not exist in the current week
  if (!currentWeek.find(el => el.day == day)) {

    // if not, add it
    currentWeek.push({value: 0, day});
  }
}

A fiddle example