Question

I’m writing code to set up a lookup structure in Javascript

var g_Codes = {
    "Type1": {
        "U.S.": "US1",
        "Asia": "AS1",
        "Europe": "EU1"
    },
    "Type2": {
        "U.S.": "X2",
        "Asia": "X2",
        "Europe": "X2"
    },
    "Type3": {
        "U.S.": "X3",
        "Asia": "X3",
        "Europe": "X3"
    },
    "Type4": {
        //  Does not exist yet
    }
};

So you can loop over this and get the code out by cross-referencing type & region.

However, I’d like to make it so I can do this:

var US_REGION = "U.S.";
var AS_REGION = "Asia";
var EU_REGION = "Europe";

var g_Codes = {
    "Type1": {
        US_REGION: "US1",
        AS_REGION: "AS1",
        EU_REGION: "EU1"
    },
    "Type2": {
        US_REGION: "X2",
        AS_REGION: "X2",
        EU_REGION: "X2"
    },
    "Type3": {
        US_REGION: "X3",
        AS_REGION: "X3",
        EU_REGION: "X3"
    },
    "Type4": {
        //  Does not exist yet
    }
};

and make it easier to change the standard region names.

If I try this:

for(let focus in g_Codes) {
     print(focus);
}

The first gives me “U.S.”, “Asia”, etc, while the second gives “US_REGION”, “AS_REGION”

How can I use the variables, but keep the simplicity of looping over g_Codes?

Answer 1

You can’t, in the notation you want.

You can define the object first:

var g_Codes = {
    Type1: {},
    Type2: {},
    Type3: {}
};

And then populate it using variables for property names and square bracket notation:

g_Codes.Type1[US_REGION] = 'US1';