Storing a Key Value Array into a compact JSON string
I want to store an array of key value items, a common way to do this could be something like:
// the JSON data may store several data types, not just key value lists,
// but, must be able to identify some data as a key value list
// --> more "common" way to store a key value array
{
[
{"key": "slide0001.html", "value": "Looking Ahead"},
{"key": "slide0008.html", "value": "Forecast"},
{"key": "slide0021.html", "value": "Summary"},
// another THOUSANDS KEY VALUE PAIRS
// ...
],
"otherdata" : { "one": "1", "two": "2", "three": "3" }
}
But, when there is many pairs / items, the string length becomes prohibited, and I want a compact way, this could be an example:
// --> (1) a "compact" way to store a key value array
{
[
{"slide0001.html", "Looking Ahe开发者_运维技巧ad"},
{"slide0008.html", "Forecast"},
{"slide0021.html", "Summary"},
// another THOUSANDS KEY VALUE PAIRS
// ...
],
"otherdata" : { "one": "1", "two": "2", "three": "3" }
}
Additionally, I want a way to identify the data as a keyvalue array, because, I may want to store other data in the same JSON file. I have these examples:
// --> (2) a "compact" way to store a key value array
{
"keyvaluelist":
[
{"slide0001.html", "Looking Ahead"},
{"slide0008.html", "Forecast"},
{"slide0021.html", "Summary"},
// another THOUSANDS KEY VALUE PAIRS
// ...
],
"otherdata" : { "one": "1", "two": "2", "three": "3" }
}
// --> (3) a "compact" way to store a key value array
{
"mylist":
{
"type": "keyvaluearray",
"data":
[
{"slide0001.html", "Looking Ahead"},
{"slide0008.html", "Forecast"},
{"slide0021.html", "Summary"},
// another THOUSANDS KEY VALUE PAIRS
// ...
]
},
"otherdata" : { "one": "1", "two": "2", "three": "3" }
}
What do you thing, which one do you suggest, do you have another way ? Thanks.
UPDATE 1: Remove invalid code. Javascript => JSON
UPDATE 2: Add non key value data
UPDATE 3: Replace "[" and "]" for "{" and "}" in each key value pair
So why don't you simply use a key-value literal?
var params = {
'slide0001.html': 'Looking Ahead',
'slide0002.html': 'Forecase',
...
};
return params['slide0001.html']; // returns: Looking Ahead
If the logic parsing this knows that {"key": "slide0001.html", "value": "Looking Ahead"}
is a key/value pair, then you could transform it in an array and hold a few constants specifying which index maps to which key.
For example:
var data = ["slide0001.html", "Looking Ahead"];
var C_KEY = 0;
var C_VALUE = 1;
var value = data[C_VALUE];
So, now, your data can be:
[
["slide0001.html", "Looking Ahead"],
["slide0008.html", "Forecast"],
["slide0021.html", "Summary"]
]
If your parsing logic doesn't know ahead of time about the structure of the data, you can add some metadata to describe it. For example:
{ meta: { keys: [ "key", "value" ] },
data: [
["slide0001.html", "Looking Ahead"],
["slide0008.html", "Forecast"],
["slide0021.html", "Summary"]
]
}
... which would then be handled by the parser.
To me, this is the most "natural" way to structure such data in JSON, provided that all of the keys are strings.
{
"keyvaluelist": {
"slide0001.html": "Looking Ahead",
"slide0008.html": "Forecast",
"slide0021.html": "Summary"
},
"otherdata": {
"one": "1",
"two": "2",
"three": "3"
},
"anotherthing": "thing1",
"onelastthing": "thing2"
}
I read this as
a JSON object with four elements
element 1 is a map of key/value pairs named "keyvaluelist",
element 2 is a map of key/value pairs named "otherdata",
element 3 is a string named "anotherthing",
element 4 is a string named "onelastthing"
The first element or second element could alternatively be described as objects themselves, of course, with three elements each.
For use key/value pair in json use an object and don't use array
Find name/value in array is hard but in object is easy
Ex:
var exObj = {
"mainData": {
"slide0001.html": "Looking Ahead",
"slide0008.html": "Forecast",
"slide0021.html": "Summary",
// another THOUSANDS KEY VALUE PAIRS
// ...
},
"otherdata" : { "one": "1", "two": "2", "three": "3" }
};
var mainData = exObj.mainData;
// for use:
Object.keys(mainData).forEach(function(n,i){
var v = mainData[n];
console.log('name' + i + ': ' + n + ', value' + i + ': ' + v);
});
// and string length is minimum
console.log(JSON.stringify(exObj));
console.log(JSON.stringify(exObj).length);
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