Floating point number calculation

Question

I'm new to working with bitcoin and I made a javascript that adds 10 satoshi every second and then it displays on the screen in BTC.

Can someone show me why it starts showing strange numbers and then the decimal points are incorrect? I need it to start with 0.00000010 BTC

 var start = 0; window.setInterval( function() { start = start + 10; var btc = start / 100000000; console.log(btc + " BTC"); }, 1000); 

Answer 1

By using toFixed() you get the results:-)

 var start = 0 ; window.setInterval(function () { start = start + 10; var btc = parseFloat(start / 100000000).toFixed(8); console.log(btc + " BTC"); }, 1000); 

Answer 2

toFixed() method will do the trick in this case, and you will also have to increment with 0.00000010 if you want it to start from that. See the working snippet below please:

 var start = 0; window.setInterval( function() { start = start + 0.00000010; var btc = start.toFixed(8); document.getElementById("start").innerHTML = btc + " BTC"; }, 1000); 

 <p id='start'></p>