Javascript使数据结构具有动态变量

Question

[
    {
        "day": 0,
        "periods": [
            {
                "start": "01:00",
                "end": "02:00",
                "title": "",
                "backgroundColor": "rgba(254, 0, 0, 0.7)",
                "borderColor": "rgb(42, 60, 255)",
                "textColor": "rgb(0, 0, 0)"
            },
            {
                "start": "02:30",
                "end": "03:00",
                "title": "",
                "backgroundColor": "rgba(254, 0, 0, 0.7)",
                "borderColor": "rgb(42, 60, 255)",
                "textColor": "rgb(0, 0, 0)"
            }
        ]
    },
    {
        "day": 1,
        "periods": [
            {
                "start": "01:00",
                "end": "02:00",
                "title": "",
                "backgroundColor": "rgba(254, 0, 0, 0.7)",
                "borderColor": "rgb(42, 60, 255)",
                "textColor": "rgb(0, 0, 0)"
            }
        ]
    },
    {
        "day": 2,
        "periods": [
            {
                "start": "01:00",
                "end": "01:30",
                "title": "",
                "backgroundColor": "rgba(254, 0, 0, 0.7)",
                "borderColor": "rgb(42, 60, 255)",
                "textColor": "rgb(0, 0, 0)"
            }
        ]
    },
    {
        "day": 3,
        "periods": [
            {
                "start": "02:00",
                "end": "02:30",
                "title": "",
                "backgroundColor": "rgba(254, 0, 0, 0.7)",
                "borderColor": "rgb(42, 60, 255)",
                "textColor": "rgb(0, 0, 0)"
            }
        ]
    },
    {
        "day": 4,
        "periods": [
            {
                "start": "01:00",
                "end": "01:30",
                "title": "",
                "backgroundColor": "rgba(254, 0, 0, 0.7)",
                "borderColor": "rgb(42, 60, 255)",
                "textColor": "rgb(0, 0, 0)"
            }
        ]
    },
    {
        "day": 5,
        "periods": [
            {
                "start": "01:30",
                "end": "02:00",
                "title": "",
                "backgroundColor": "rgba(254, 0, 0, 0.7)",
                "borderColor": "rgb(42, 60, 255)",
                "textColor": "rgb(0, 0, 0)"
            },
            {
                "start": "03:00",
                "end": "03:30",
                "title": "",
                "backgroundColor": "rgba(254, 0, 0, 0.7)",
                "borderColor": "rgb(42, 60, 255)",
                "textColor": "rgb(0, 0, 0)"
            }
        ]
    },
    {
        "day": 6,
        "periods": []
    }
]

How to make such data structure with dynamic variables in Javascript? Lets say: I need to change periods[start] and periods[end] times in day:6 or day:2 I want to make new data2 structure like data,but with my variables of time. something like this :

for (var i=0; i <arr.legth; ++i){

    data2="'[{"day":MYVARIABLE1,"periods":[{"start":"MYVARIABLE2","end":"MYVARIABLE3",  ...}]';

}

Answer 1

It's a bit unclear what you're trying to achieve. For example, the value of the property "periods" is an array. So, periods[start] doesn't make a lot of sense, because it's not quite clear are you trying to update all periods with a new value for start property or just a particular period or what?

It might be a good idea to convert your JSON into a dictionary , so you can do something like:

var day = 2;
data[day].periods[???].start = "01:00";

I've left some question marks intentionally, for you to see that periods is an array, and you have to deal with it in that fashion.

Answer 2

Please have a look at the below test code.

You can easily understand it. Finally, I have used your provided code after this. The code focuses on concatenation of variables and strings.

There are other methods too. You can comment if you need more help.

> var a = 67
undefined
> var name = 'JavaScript'
undefined
>
> a + ""
'67'
> a + name
'67JavaScript'
> "'" + name + "'"
'\'JavaScript\''
>
> '"' + name + '"'
'"JavaScript"'
>
> var obj = '{ "name": "Rishikesh", "age": 26}'
undefined
> obj
'{ "name": "Rishikesh", "age": 26}'
>
> typeof obj
'string'
>
> // Coversion in real JS object
undefined
> realObj = JSON.parse(obj);
{ name: 'Rishikesh', age: 26 }
>
> realObj.name
'Rishikesh'
>
> realObj.age
26
>

Note: Make sure, you have properly used quotes ' and " .

// A sample test code 
var arr = [67]; // Array of 1 item

var MYVARIABLE1 = 'Wednesday'
var MYVARIABLE2 = '01:05'
var MYVARIABLE3 = '02:06'
var data2 = null;

for (var i=0; i < arr.length; ++i){
    data2 = '[{' +
            '"day": "' + MYVARIABLE1 + '",' + 
            '"periods":[{' +
                    '"start":"' + MYVARIABLE2 + '",' +
                    '"end":"' + MYVARIABLE3 + '"' +
                    '}]' + 
          '}]';
}

console.log(data2)
// [{"day": "Wednesday","periods":[{"start":"01:05","end":"02:06"}]}]