Creating new array based on another array values

I have an array of weekday indices (consisting of the numbers 0-6) that need to be converted to the appropriate corresponding 3-letter weekday strings.

For instance, the array [0, 1, 2, 3, 4, 5, 6] should be converted to ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"], and [2,4] should be converted to ["Wed","Fri"]. This is my given input data:

 "data":[
        {
           "name":"John",
           "gender":"M",
           "age":"40",
           "days_present":[0,1,2,3,4,5,6],
           "time_spend":1626908399000
        },
     {
           "name":"Maria",
           "gender":"F",
           "age":"32",
           "days_present":[2,6],
           "time_spend":1626908366000
        },
      {
           "name":"Ben",
           "gender":"M",
           "age":"27",
           "days_present":[2,4,6],
           "time_spend":1626908331000
        }
  ]

And the resultant data should appear as follows:

  "data":[
        {
           "name":"John",
           "gender":"M",
           "age":"40",
           "days_present":["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"],
           "time_spend":1626908399000
        },
     {
           "name":"Maria",
           "gender":"F",
           "age":"32",
           "days_present":["Wed","Sun"],
           "time_spend":1626908366000
        },
      {
           "name":"Ben",
           "gender":"M",
           "age":"27",
           "days_present":["Wed", "Fri","Sun"],
           "time_spend":1626908331000
        }
  ]

How should I best go about doing this?

CodePudding user response：

Pretty simple, just do two map calls:

const obj={"data":[{"name":"John","gender":"M","age":"40","days_present":[0,1,2,3,4,5,6],"time_spend":1626908399000},{"name":"Maria","gender":"F","age":"32","days_present":[2,6],"time_spend":1626908366000},{"name":"Ben","gender":"M","age":"27","days_present":[2,4,6],"time_spend":1626908331000}]};

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

const result = obj.data.map(({ days_present, ...r }) => ({
  days_present: days_present.map(i => weekdays[i]),
  ...r
}));

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: auto; }

This loops over each item in data and converts each of the weekday indices to their corresponding weekday string.