How to call a variable in another function?

var temperature;
var toTemperature;

function onUpdate(dc) {
dc.drawBitmap(38, 65, Ui.loadResource( Rez.Drawables.cloud_icon ));
dc.setColor(Graphics.COLOR_BLACK, Graphics.COLOR_GREEN);

onTemperature(ie);
dc.drawText(50, 85, Graphics.FONT_XTINY, toTemperature+"°", Graphics.TEXT_JUSTIFY_CENTER);
}

function onTemperature(ie) {
temperature = ie[0]["current"]["temperature"];
toTemperature = temperature.toString();
}

you have to call your function somewhere so that the var toTemperature can be filled

I've tried this method before, but it still doesn't work :

Error: Symbol Not Found Error

Details: Could not find symbol 'ie'

You need to set the variable to something.  care you getting the weather data from something like a makeWebResuest/

You pass that in the call to your onTemerature function.

say "myData" has what you got from the makeWebRequest, then you would make the call:

onTemperature(myData);

in onUpdate()

of course, you have to set ie first, it seems to be the array where are saved your weather data.

this as suggested by Shent-Aurkhan (SHN) above?
if yes, I have done but still null.

but when I do : Sys.println(ie) inside function onTemperature(ie), data is ok and show

in the model, I made it like this :

function onReceiveData(responseCode, data) {

    if(responseCode == 200) {

        if(ie == null) {
    
            ie = new.TemperatureMonitoring();
    
        }

        for( var i = 0; i < 1; i++ ) {
    
            ie.sampleData = [data];
    
        }

        notify.invoke(ie.sampleData);
    
    }else {
    
        Sys.println("Data request failed\nwith response : ");
    
        Sys.println(responseCode);
    
    }

}

the 2 functions (onUpdate and onTemperature) are they in the same class?

yes in same class