How do I iterate over this json structure to produce another structure?

问题

I have this json structure.

x=[{
    "value": 1.37,
    "date_transacted": "2015-01-01"
}]

From this json structure, I want to produce the following json structure;

y1=[{
    c: [{
        v: "2015-01-01"
    },
    {
        v: "1.37"
    }]
}]

I have written the code to do this. It looks like this;

var y1 = [{ c:[ {"v":x[0].value}, {"v":x[0].date_transacted} ] }];

My problem comes when x has several json key/value pairs. Something that look like this;

x=[{
    "value": 1.37,
    "date_transacted": "2015-01-01"
},
{
    "value": 1.62,
    "date_transacted": "2015-02-01"
},
{
    "value": 1.83,
    "date_transacted": "2015-03-01"
}]

What is an effective way to iterate my code through the array of objects to produce the desired json structure which should look like this?

y=[{
    c: [{
        v: "2015-01-01"
    },
    {
        v: "1.37"
    }]
},
{
    c: [{
        v: "2015-01-02"
    },
    {
        v: "1.62"
    }]
},
{
    c: [{
        v: "2015-01-03"
    },
    {
        v: "1.83"
    }]
}]

回答1:

The other answers here (except @user2415266) are not dynamic, hard-coded to accept an exact input, and are not particularly reusable. They will fail if you have more than 2 properties, or in @Siguza's case, also if you have properties not called 'date_transacted' and 'value'.

function restructureJson(obj) {
    var output = {c:[]};
    for (var i in obj) {
        output.c.push({v:obj[i]});
    }
    return output;
}

This function is reusable on any array of objects, of any size, containing any number of properties.

// Simple example
var json1 = [{
    "value": 1.37,
    "date_transacted": "2015-01-01"
}];

// More complex
var json2 = [{
    "value": 1.37,
    "date_transacted": "2015-01-01",
    "another_value": "test",
    "more": "12356"
},
{
    "value": 1.62
},
{
    "value": 1.83,
    "date_transacted": "2015-03-01",
    "stuff": "124334654567"
}];

// Map the function to the arrays
a = json1.map(restructureJson);
b = json2.map(restructureJson);

回答2:

var y1=[]; 
for(var i=0;i<x.length;i++){

   y1[i]= [{ c:[ {"v":x[i].value}, {"v":x[i].date_transacted} ] }];

}

回答3:

As a single statement:

y = x.map(function(e)
{
    return {
        c:
        [
            {
                v: e.value
            },
            {
                v: e.date_transacted
            }
        ]
    };
});

回答4:

Both other answers only work if the objects in x have the exact 2 properties. A way to do it regardless of the amount of properties:

y = [];
for(var i = 0, i < x.length; i++){
    var obj = {c:[]};
    for(var prop in x[i]){
        obj.c.push({v:x[i][prop]})
    }
    y.push(obj);
}

Edit: with map

y = x.map(function(e)
{
    var obj = {c: []};
    for(var prop in e){
        obj.c.push({v:e[prop]})
    }
    return obj;
});

来源：https://stackoverflow.com/questions/33298774/how-do-i-iterate-over-this-json-structure-to-produce-another-structure