getting access to javascript object property beginning with number

Question

I am calling an api which returns an object

var rain = data[i].rain;

$.get( "http://api.openweathermap.org/data/2.5/forecast?q=London,uk&mode=json&units=metric", function( data ) {
    var data = data.list;
    for(var i = 0; i < 12; i++){
        var rain = data[i].rain;
        console.log(rain)
    }
});

rain returns the following when I inspect the console:

Object {3h: 0.005}
Object {3h: 0.03}

I expected that rain.3h would have given me access to 0.005 and 0.03, but it doesn't. I get the following error message : Unexpected token ILLEGAL

Is this because it begins with a number? Can anyone advise how to access this property?

You can only use dot notation to access properties if the property name is a valid identifier. `'3h'` isn't, so use square bracket notation. — RobG, Jun 16 '15 at 20:47
@RobG so you can always use the bracket notation, but the dot notation only in certain circumstances? — Paul Fitzgerald, Jun 16 '15 at 20:52
Related: [How to access object properties containing special characters?](http://stackoverflow.com/q/12953704/218196) — Felix Kling, Jun 16 '15 at 20:55

pietrovismara · Accepted Answer · 2015-06-16T20:50:36.353

2

Yes it's because it begins with a number.

You can access that like this:

rain['3h']

When you have object properties named with numbers or simbols, use the bracket notation.

edited Jun 16 '15 at 20:50

answered Jun 16 '15 at 20:45

pietrovismara

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Uncaught TypeError: Cannot read property '3h' of undefined returns this error – Paul Fitzgerald Jun 16 '15 at 20:47
1

`data[i].rain['3h']` perhaps? – RobG Jun 16 '15 at 20:48
yes, all good, got it. thanks, will upvote when the time allows me to – Paul Fitzgerald Jun 16 '15 at 20:49

getting access to javascript object property beginning with number

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