JS same function different parameters in every object value. How can I write less?

Question

What I did

I call a function in objects' value.

And this function would be called in every object as much as users add an absent data.

What I want to do

Hence I recognize that I could have thousands of hundred of new object, I would rather minimize/eliminate duplication than write the function every time.

Explain what the code is for

The function's name I would like to auto-set is datesBetween().

datesBetween() can choose the mode, and it has parameters.

The mode refers the value from the key reason which is in same object. arr[0].absent[0].datesBetween's value should be datesBetween('leave')('2020-1-1','2020-1-4').

The parameters does same. First parameter should refer from the object key start which is in same object, second parameter should refer from the object key end.

Some idea

I guess this could use class but I am afraid to mix up with functions. if class would help, please do tell.

I write this thou, I am uncertain about this. Is using this could be a solution in this code?

var arr = [
  {
    name : "A", 
    absent :[ 
      {
        reason : "leave",
        start : '2020-1-1',
        end : '2020-1-4',
        datesBetween : datesBetween('leave')(this.start, this.end)
      }, {
        reason : "sleeOver",
        start : '2020-1-25',
        end : '2020-1-26',
        datesBetween : datesBetween('sleeOver')(this.start, this.end)
      }    
    ]
  }, {
    name : "B", 
    absent :[
      {
        reason : "weekendExcursion",
        start : '2020-1-18',
        end : '2020-1-19',
        datesBetween : datesBetween('weekendExcursion')(this.start, this.end)
      }
    ]
  }  
]

function autoAbsentSetter(){
  //do I need class to use inheritance/property things?
  
}

function addAbsent(mode){
  var funcs = {
    'leave' : function absent_leave(name, absentName, absentStart, absentEnd){ //all kinds of leave are included. Detail further.
    //some codes
    },
    'sleepOver' : function absent_sleepOver(name, absentName, absentStart, absentEnd){
    //some codes
    },
    'weekdayExcursion' : function absent_weekdayExcursion(name, absentName, absentStart, absentEnd){
    //some codes
    },
    'weekendExcursion' : function absent_weekendExcursion(name, absentName, absentStart, absentEnd){
    //some codes
    }
  }
  return funcs[mode];
}

What your after is something called prototype, a class is pretty much the same thing but nicer syntax.. — Keith, Jun 21 '20 at 14:55

score 0 · Answer 1 · answered Jun 21 '20 at 16:08

You don't need to put those functions inside the array literal (and yes, you cannot access the other properties there anyway). Just write

var arr = [
  {
    name: "A", 
    absent: [ 
      {
        reason : "leave",
        start : '2020-1-1',
        end : '2020-1-4',
      }, {
        reason : "sleepOver",
        start : '2020-1-25',
        end : '2020-1-26',
      }    
    ]
  }, {
    name: "B", 
    absent: [
      {
        reason : "weekendExcursion",
        start : '2020-1-18',
        end : '2020-1-19',
      }
    ]
  }  
];

for (const value of arr) {
  for (const absence of value.absent) {
    absence.datesBetween = datesBetween(absence.reason)(absence.start, absence.end);
  }
}

You can do whatever you want in that loop processing your data.

JS same function different parameters in every object value. How can I write less?

1 Answers1