CODEWITHSUNDEEP
javascriptjson
Rio
Rio

Reputation: 14882

Access dynamically named JavaScript Objects?

I have a JS Object:

var testObj = new Object();

that has a property called volume1, so

testObj.volume1

has a value. How would I go about accessing that property by using something along the lines of 

testObj.volume + "1"

To give it more context, the object actually has more properties, like

testObj.volume1, testObj.volume2 and testObj.volume3

and I want to access them using some iteration. I've tried playing with the window[] element, but have had not much success.

Thanks!

Upvotes: 3

Views: 206

Answers (4)

hojberg
hojberg

Reputation: 1124

off topic it is considered better pratice to do 

var testObj = {};

instead of

var testObj = new Object();

Upvotes: 2

NawaMan
NawaMan

Reputation: 25687

You can use for loop with in operation.

for(var PropName in testObj) {
    var PropValue = testObj[PropName];
    ....
}

In case, you only want the property with the name started with 'value' only, you can also do this:

for(var PropName in testObj) {
    if (!/^value[0-9]$/.match(PropName))
        continue;
    var PropValue = testObj[PropName];
    ....
}

OR if the number after the 'value' is always continuous you can just use a basic for loop.

for(var I = 0; I <= LastIndex; I++) {
    var PropName  = "value" + I;
    var PropValue = testObj[PropName];
    ....
}

Hope this helps.

Upvotes: -1

Tomas Vana
Tomas Vana

Reputation: 18775

Use something in the fashion of testObj["volume" + "1"] ;)

The notations object.property and object["property"] are (almost) equivalent in javascript.

Upvotes: 0

user187291
user187291

Reputation: 53940

   testObj["volume" + 1]

but you actually want an array here

   testObj.volume = [...]
   testObj.volume[1] = whatever

Upvotes: 7

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