JavaScript object value based on variable

Question

I have a variable named day. It contains the current day (i.e. "Wednesday") as a string. I also have an object called data. When I alert data.Wednesday it gives me the total count for that day.

alert(data.Wednesday); //alerts 2

I want the count for the current day (not the hard-coded Wednesday). My question is, how do I replace data.Wednesday with data.day. I obviously cant do data.day because day isn't an element of the data object. Is there any way to do this? Thanks in advance.

Ugh, wrong duplicate. This is the correct one: http://stackoverflow.com/q/4244896/218196. Someone else please close. — Felix Kling, Jun 25 '15 at 02:55

score 2 · Accepted Answer · answered Jun 25 '15 at 02:53

2

You have to access the property by using squared brackets.

var day = "Wednesday";
alert(data[day]);

answered Jun 25 '15 at 02:53

Sebastian Nette

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score 2 · Answer 2 · answered Jun 25 '15 at 02:53

2

To let JS evaluate your expression and lookup a property with the value use square bracket notation

var data = {someValue: 'Wednesday'};
var day = 'someValue';
data[day]; // 'Wednesday'

Where someValue can be a string or a number.

answered Jun 25 '15 at 02:53

t3dodson

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JavaScript object value based on variable

2 Answers2