Converting string to double

Former Member over 8 years ago

Hi,
I want to convert a "string" number to double, but I'm getting an error.
Here is an example:

var x="1.0";
var p = x.toDouble();

The last code explode with the next error message:

Could not find symbol toDouble.
Symbol Not Found Error

But if I use toFloat() instead of toDouble it works ok.

var x="1.0";
var p = x.toFloat();

Any ideas to convert a string to double?

Thanks!

Top Replies

jim_m_58 over 5 years ago in reply to Skimans +1

You need to use

var peso = test.toFloat().toDouble();
jim_m_58 over 5 years ago in reply to Skimans +1
I think you're confusing a value and displaying a value. Consider this:
```
var str="5.2";
var val=str.toFloat().toDouble();
Sys.println("val="+val+" with format="+val.format("%0.1f"));…
```

All Replies

travis.vitek over 8 years ago

As you've noticed, Lang.String doesn't have a toDouble() method. If you don't mind the loss of precision, you can just write..

s.toFloat().toDouble()

If you care about precision, but you don't need to read the unusual formats (like 1.123e10), something like this should work...

function string_toDouble(s) {

    var decimal_point = s.find(".");
    if (decimal_point == null) {
        return s.toNumber().toDouble();
    }

    var pfx = s.substring(0, decimal_point);
    var sfx = s.substring(decimal_point + 1, s.length());

    return pfx.toNumber() + sfx.toNumber() / Math.pow(10.0d, sfx.length());
}

function do_test_to_double(logger, s, e)
{
    var r = string_toDouble(s);
    Test.assertMessage(r instanceof Lang.Double, "Expected a double");
    Test.assertEqualMessage(r, e, Lang.format("Converting '$1$' to double got $2$, expected $3$", [ s, r, e ]));
}

(:test) function test_to_double(logger)
{
    do_test_to_double(logger, "123", 123.0d);
    do_test_to_double(logger, "123.123", 123.123d);
    do_test_to_double(logger, "1.123456789", 1.123456789d);

    return true;
}

Travis

Skimans over 5 years ago

ihave the same problem of Wearapps.

I must convert string text in double format. in particulary numbers with 1 decimal (for example: 5.2) and register to Properties.

function onTextEntered(text, changed) {
var peso = text.toFloat.toDouble();
Properties.setValue(DefaultPropertiesView.DOUBLE_PROP, peso );
}

in this way not works...

how i can resolve ?

jim_m_58 over 5 years ago in reply to Skimans

You need to use

var peso = test.toFloat().toDouble();

Travis.ConnectIQ over 5 years ago

I found an issue to add String.toLong() and String.toDouble() in our backlog (WERETECH-1728). This should be an easy fix, so I'll see what I can do about getting it added to the API.

Skimans over 5 years ago in reply to jim_m_58

return to me value always value+five zeros....5.200000

this is Settings.xml:

this is Properties.xml:

<strings>
<string id="double_title">Double</string>
</strings>

jim_m_58 over 5 years ago in reply to Skimans

I think you're confusing a value and displaying a value. Consider this:

var str="5.2";
var val=str.toFloat().toDouble();
Sys.println("val="+val+" with format="+val.format("%0.1f"));

What's output is:

val=5.20000 with format=5.2

When doing math, you'll want to use "val", but for display, you probably want to convert val to a string with a specific format.

By the way, what is actually happening with the println, is that the

"val="+val

is in effect doing

"val="+val.toString()

to get a string to display

Skimans over 5 years ago in reply to jim_m_58

Yes Jim. Are first steps in MonkeyC. I'm beginner!!

For now i have resolved in this way for read value from Properties:

var app = Application.getApp();
var string = app.getProperty("string_prop");
var peso2 = string.toFloat();

and after for view:

dc.drawText(120,170, Graphics.FONT_SMALL, peso2.format("%.01f") , Graphics.TEXT_JUSTIFY_CENTER);

but now 'im not interested to view value. I need value (peso2) for use it in one formula.

Thanks for infos!