How do I check an array for multiple values in Javascript (avoid using too many "or" statements)

Question

I have 2 select list drop downs. Select list A has 10 values (int). If a certain selection is made aka: a specific value, then I want to Select list B to be hidden. Right now I have the hiding functionality, if I use multiple "||" or statements, but this is messy and no good practice. How do I check if a specific value is chosen without using a bunch of or statements?

Current Code (working but ugly):

$('#status').change(function(){
            let $appStatus = $('#status').val();

        if($appStatus == 400 || $appStatus == 606 || $appStatus == 620 || $appStatus == 700 || $appStatus == 1000 || $appStatus == 1020){
          console.log(true);
          $reasonNoHire.hide()
        }else{
          console.log(false);
          $reasonNoHire.show();
        }
      });

Other code I have tried by always returns false

            //Brought back depending on what the user chooses in Selectlist A
            let $appStatus = $('#status').val();
            let valArray = [400, 606, 620, 700, 1000, 1020];

            if(valArray.includes($appStatus)){
              console.log(true);
              $reasonNoHire.hide()
            }else{
              console.log(false);
              $reasonNoHire.show();
            }
          });

Why would the 2nd chunk return false? Can you `console.log($appStatus);` and see why? — TRose, Oct 08 '19 at 19:50
Yeah, the code looks correct. Good job being on the right track. Log $appStatus right after you declare it. — Tanner, Oct 08 '19 at 19:51
`$appStatus` would be a string and you have an array of numbers. Either convert `$appStatus` to a number or make your array only have strings. — VLAZ, Oct 08 '19 at 19:52
Possible duplicate of [How do I check if an array includes an object in JavaScript?](https://stackoverflow.com/questions/237104/how-do-i-check-if-an-array-includes-an-object-in-javascript) — Heretic Monkey, Oct 08 '19 at 19:55

score 3 · Accepted Answer · answered Oct 08 '19 at 19:52

3

The problem is that $appStatus is a string and not a number. This happens to pass in your first example because you are using == instead of ===. Array.prototype.includes returns false because [400].includes('400') is comparing a string to a number.

answered Oct 08 '19 at 19:52

KevBot

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adiga · Answer 2 · 2019-10-08T20:00:08.543

1

$('#status').val() returns a string but you are comparing it against numbers. You are using loose equality in the first snippet. So, it works. But, includes uses Same-value-zero algorithm to compare (Almost equal to Strict Equality). So, change the array to an array of strings or convert the value to a number before checking includes

edited Oct 08 '19 at 20:00

answered Oct 08 '19 at 19:53

adiga

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How do I check an array for multiple values in Javascript (avoid using too many "or" statements)

2 Answers2