Count the number of elements inside of a JSON string [duplicate]

Question

I have a JSON string that represents a datatable with one row. Here's the table:

"MyData":[
    {
        "FirstName":"John",
        "LastName":"Doe",
        "ID":1234,
        "QCR3m":null,
        "FR3m":null,
        "ERI3m":null,
        "QCR6m":null,
        "FR6m":null,
        "ERI6m":null,
        "QCR1y":90.05,
        "FR1y":null,
        "ERI1y":93.55,
        "QCR3y":93.51,
        "FR3y":95.86,
        "ERI3y":94.0,
        "QCR5y":93.25,
        "FR5y":95.86,
        "ERI5y":94.0
    }
]

I want to count the number of columns in MyData. In this case the number would be 18. Is this possible to do in javascript?

Answer 1

Use Object.keys with length

var obj = {
        "FirstName":"John",
        "LastName":"Doe",
        "ID":1234,
        "QCR3m":null,
        "FR3m":null,
        "ERI3m":null,
        "QCR6m":null,
        "FR6m":null,
        "ERI6m":null,
        "QCR1y":90.05,
        "FR1y":null,
        "ERI1y":93.55,
        "QCR3y":93.51,
        "FR3y":95.86,
        "ERI3y":94.0,
        "QCR5y":93.25,
        "FR5y":95.86,
        "ERI5y":94.0
    };

console.log(Object.keys(obj).length);