Finding and Storing JSON Nested Arrays When Names Unknown

Question

Sorry if this has been answered elsewhere here, I have not found it if it has been. I have valid JSON:

{
    "main": [
        {
            "Example1": [
                {
                    "Example1_Var02": "5",
                    "Example1_Var09": "443",
                    "Example1_Var27": "23",
                    "Example1_Var01": "31"
                }
            ],
            "Example2": [
                {
                    "Example2_Var99": "2",
                    "Example2_Var84": "344",
                    "Example2_Var46": "56",
                    "Example2_Var03": "78"
                }
            ]
        }
    ]
}

whose names are unknown to me and/or will change regularly, except for the super key of "main." Assuming a successful $.ajax() call that returns "data," e.g. success: function(data) { , I would like to break out each nested array into localstorage without needing to know their key names, as I may never know them. But as it is, I cannot get something where I know those sub-array names to work. This:

for(var key in data){
   localStorage.setItem(key, JSON.stringify(data[key]));
}

will create a single localstorage instance of "main". But this (and other variations):

for(var key in data){
   localStorage.setItem(key.Example1[0], JSON.stringify(data[key.Example1]));
}   

returns an error "Uncaught TypeError: Cannot read property '0' of undefined". And since I cannot accomplish this with a known subarray key name, doing it at an abstract, anonymous level is more challenging still. How can I simply output whatever nested arrays happen to be contained in "main" to separate local storage without necessarily knowing their names in the JSON? Thanks for your help.

Answer 1

As @Pointy pointed out, if you can always expect main to be there and the structure of the object is predictable (even if the names and data aren't) you can use a for...in statement to iterate over the object:

for(var outer in x.main){ 
    for(var inner_key in x.main[outer]){ 
        localStorage.setItem(inner_key, JSON.stringify(x.main[outer][inner_key]));

    }
}

console.log(localStorage.getItem('Example1'));
// "[{"Example1_Var02":"5","Example1_Var09":"443","Example1_Var27":"23","Example1_Var01":"31"}]"