Decimal to binary code-Javascript

Question

I'm trying to learn Javascript. Why this is not working?

function test() {
  var x,z;
  $x = document.getElementById("input").value;
  $z = ($x).toString(2);
  document.getElementById("demo").innerHTML = $z;
}

<input type="text" id="input">
<button onclick="test()">Try it</button>
<p id="demo"></p>

Browser don't inser binary number but it inser what is in input. — Ľubomír Skirka
– Ľubomír Skirka, Commented Feb 21, 2015 at 19:57
So you trying to convert the input number to binary number and then insert in p? — void
– void, Commented Feb 21, 2015 at 19:58

Oriol · Accepted Answer · 2015-02-21 20:01:13Z

2

Your $x is a string, not a number.

To convert it to a number, you can use the unary + operator.

Then, toString(2) will work:

function test() {
  var $x = +document.getElementById("input").value,
      $z = $x.toString(2);
  document.getElementById("demo").innerHTML = $z;
}

<input type="text" id="input">
<button onclick="test()">Try it</button>
<p id="demo"></p>

answered Feb 21, 2015 at 20:01

Oriol

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1 Comment

Grijesh Chauhan Over a year ago

+ though I will prefer to use (+$x).toString(2); where I need $x as int

void · Accepted Answer · 2015-02-21 20:10:53Z

0

You need to convert $x to int by parseInt() this way...

$z = (parseInt($x)).toString(2);

Modified Function...

function test() {
        var x,z;
        $x = +document.getElementById("input").value;
        $z = ($x).toString(2);
        document.getElementById("demo").innerHTML = $z;
    }

Working Fiddle

edited Feb 21, 2015 at 20:10

answered Feb 21, 2015 at 19:59

void

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Decimal to binary code-Javascript

2 Answers 2

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