how to double a float value in a inputbox

Question

i get a float value by this code

currentvalue=$("#double_your_btc_stake").val();

but when i try to write double of the old value

currentvalue*=2;$("#double_your_btc_stake").val(currentvalue);

but it write to input box

2e-8

what i do wrong

http://jsfiddle.net/62jJM/

You do not have a float, you have a string that the browser changes to a number when you multiply. :) — epascarello, Nov 20 '13 at 14:32
[Your code should work fine.](http://jsfiddle.net/) You may have left out some important details. — Pointy, Nov 20 '13 at 14:32
What is the value in the textbox to start out? IS there other logic, make a example that shows the error. [JSFiddle.net](http://JSFiddle.net) — epascarello, Nov 20 '13 at 14:35

score 0 · Answer 1 · edited May 23 '17 at 12:12

Try this out:- http://jsfiddle.net/adiioo7/LCmjG/1/

JS:-

jQuery(function ($) {
    $("#Double").on("click", function () {
        var currentvalue = $("#double_your_btc_stake").val();
        currentvalue *= 2;
        $("#double_your_btc_stake").val(longnumberstring(currentvalue));
    });
});

function longnumberstring(n) {
    var str, str2 = '',
        data = n.toExponential().replace('.', '').split(/e/i);
    str = data[0], mag = Number(data[1]);
    if (mag >= 0 && str.length > mag) {
        mag += 1;
        return str.substring(0, mag) + '.' + str.substring(mag);
    }
    if (mag < 0) {
        while (++mag) str2 += '0';
        return '0.' + str2 + str;
    }
    mag = (mag - str.length) + 1;
    while (mag > str2.length) {
        str2 += '0';
    }
    return str + str2;
}

HTML:-

<input type="text" id="double_your_btc_stake" style="width:500px" />
<input type="button" id="Double" value="Double" />

Used Reference to convert the exponential to long string.

@user2061745 Does this answer your question? – Aditya Singh Nov 21 '13 at 05:49 — Aditya Singh, Nov 21 '13 at 05:49

Shoaib Chikate · Answer 2 · 2013-11-20T15:00:10.880

-2

Simply use this:

parseFloat($("#yourId").val())

edited Nov 20 '13 at 15:00

answered Nov 20 '13 at 14:33

Shoaib Chikate

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2

This should not be necessary. The multiplication will implicitly convert the string to a number (if it's a valid number of course). – Pointy Nov 20 '13 at 14:34

how to double a float value in a inputbox

2 Answers2

Try this out:- http://jsfiddle.net/adiioo7/LCmjG/1/