locked
Why is this code always false? RRS feed

 > 

  • Question

  • Question
    Sign in to vote
    0
    Sign in to vote
    User-2049827838 posted
    <!DOCTYPE html>
<html lang="en">
<head>
    <title>test</title>
</head>
<body>
    <p id="answer"></p>

    <input type="text" id="Power" />

    <button type="button"onclick="test()">test</button>



    <script>
        


       function test() {
            

            var strength = document.getElementById("Power").value;
            var arr = [4.5, 5, 6.5]

            if (arr.includes(strength)) {

                document.getElementById("answer").innerHTML = ("result");
                
            }


            else {
                document.getElementById("answer").innerHTML = ("nothing");
                alert("Hello World");
            }

               
               
            
        }
    </script>


</body>
</html>

    Saturday, April 6, 2019 8:44 PM

Answers

All replies

  • Question
    Sign in to vote
    0
    Sign in to vote
    User-943250815 posted

    You can´t compare String with Number type, convert String to Number then compare
    https://gomakethings.com/converting-strings-to-numbers-with-vanilla-javascript/

    • Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM
    Saturday, April 6, 2019 10:56 PM
  • Question
    Sign in to vote
    0
    Sign in to vote
    User-2054057000 posted

    I checked your code and did not find any problem. I have described the working of the cod below , check it:

    var arr = [4.5, 5, 6.5]
var strength = 4.5
console.log(arr.includes(strength)) // returns true
    var arr = [4.5, 5, 6.5]
var strength = 2
console.log(arr.includes(strength)) // returns false

    Sunday, April 7, 2019 5:45 AM
  • Question
    Sign in to vote
    0
    Sign in to vote
    User-2049827838 posted

    @jzero I thought JavaScript converted on the fly, that was why you didn't need to add a type when declaring a variable so didn't consider this an option but thanks, I'll check it out.  It worked fine before I started using the text box so I'm guessing this is the problem.

    @yogiyogi It worked fine for me when I first tested it in a similar way, that's why I was so confused.

    Sunday, April 7, 2019 6:35 AM
  • Question
    Sign in to vote
    0
    Sign in to vote
    User-2049827838 posted

    Amended the offending line in the code to this and all is well

     if (arr.includes(Number(strength))) {

    Thanks guys

    • Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM
    Sunday, April 7, 2019 8:01 AM