I am making a poker game and poker-evaluator that I am using to tell me only the outcome from the cards

'invalid hand',
    'high card',
    'one pair',
    'two pairs',
    'three of a kind',
    'full house',
    'four of a kind',
    'straight flush'

I am trying to know which cards in the sets are responsible for the "win".

I made a filter for duplicates and full house (i.e. three duplicates of same number and 2 duplicates of other number).

How can I improve the quality of the code below?

     interface CardDuplicate{
      const getDuplicates =(Firsts:Array<string>,FullArray:Array<string>)=> {
          let duplicates ={} as CardDuplicate;
          for (let i = 0; i < Firsts.length; i++) {
        const key = Firsts[i] as keyof  CardDuplicate
          if(key in duplicates) {
          }else if (Firsts.lastIndexOf(key) !== i) {
              duplicates[key] = [i];
         let Type = "none";
         if(duplicates === undefined){
          return {Type:Type,Cards:[]};
           const Obj = Object.keys(duplicates).map((key)=> {
        key = key as keyof CardDuplicate
        if(duplicates !== undefined && duplicates[key] !== undefined){
  if(duplicates[key ].length > 2 && Object.keys(duplicates).length > 1){
    Type= "Full house";
  }else if( Object.keys(duplicates!).length > 2){
    Type= "three pairs";
  }else if(duplicates[key].length == 2 && Object.keys(duplicates).length > 1){
    Type= "two pairs";
  }else if(duplicates[key].length == 2 && Object.keys(duplicates).length == 1){
    Type= "one pairs";
   return duplicates[key ].map((data:string)=>{return FullArray[data]});
  return []
          return {Type:Type,Cards:Obj};
    function CheckIfPairs(Item:Array<string>){
      const Firsts:Array<string>=[];
      const Letters:Array<string>=[];
      const Number:string = data.split('')[0]
    return getDuplicates(Firsts,Item)

    //s = spades h = hearts c = clubs (♣), d= diamonds
  • \$\begingroup\$ Please start by autoformatting your code (but only before someone writes an answer) (hint: select the --parser typescript option). \$\endgroup\$
    – ggorlen
    Oct 25, 2022 at 15:49

1 Answer 1


Yes, please format the code, so it's easier to read.

Look at your duplicates === undefined. These seem overly-cautious checks. How can these occur?

It also seems like Object.keys(duplicates).length is assumed to be the number of duplicates. But it seems like it is a reverse index of cards, and there may just be a single card in the entries, so some of the logic may be off.

Hope this helps.


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