Question

I have this Javascript below, and I know that there is probably a better way of doing what I have done, so if you would like to share a better way, please do and I will definitely use it.

var Apeople = ["bob", "joe", "jane", "mike", "henry", "alex"];
var Abdays = ["08/20", "01/23", "04/19", "08/16", "01/08", "04/02"];

Apeople and Abdays line up with each other, so Janes birthday is 04/19.

I know I’m not supposed to use eval() so if you know of a better way please tell me.

var mnths = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
for(i=0; i<mnths.length; i++){
   eval("var "+mnths[i]+" = []");
}

for(i=0; i<Abdays.length; i++){
   var ab = Abdays[i];
   if(ab.substring(0,1) == "0"){
      var mn = ab.substring(1,2); //month number without 0 before it
   } else {
      var mn = ab.substring(0,2); //month number if 11 or 12
   }
   eval(""+mnths[mn-1]+".push(i)");
}

Now I have January=[1,4] April=[2,5] August=[0,3]. I did this so I can find out whos name goes with what birthday.

For example Apeople[January[0]] would be joe and Abdays[January[0]] would be 01/23.

What I need to do is put each months entries in order by which comes first going by the birthdays. Abdays[January[0]] is 01/23 but Abdays[January[1]] is 01/08 so they should be swapped.

As I am typing this I am thinking that I probably should have used JSON.

So what I need help with is putting the birthdays in order while still being able to tell which birthday goes to which name, and at the same time possibly finding a better way to write this code.

Answer 1

You can sort theAbdays array like this.

Abdays = Abdays.sort(function(a, b){
   var d1 = new Date(a + " 2010");
   var d2 = new Date(b + " 2010");
   return d1 > d2;
});

I randomly selected 2010. You will have to modify this, add more conditions if you need and write code to sort Apeople according to sorted Abdays .

UPDATE:

Quickly written. You can find better ways, but hope this helps

var map = {};
for(var i=0 ; i < Apeople.length; i++){
   map[Abdays[i]] = Apeople[i];
}

Abdays = Abdays.sort(function(a, b){      
   var d1 = new Date(a + " 2010");
   var d2 = new Date(b + " 2010");
   return d1 > d2;
});

for(var i=0 ; i < Apeople.length; i++){
   Apeople[i] = map[Abdays[i]];
}

console.log(Apeople, Abdays);