Restructuring a large amount of values in a JSON file - json

Question

I have a JSON file with a large amount of the following values:
"values": [
"Foo": 1,
"Bar": 2,
"Baz": 3,
...
],
How do I efficiently convert this into:
"values": [
{
"name": "Foo",
"value": 1
},
{
"name": "Bar",
"value": 2
},
{
"name": "Baz",
"value": 3
},
...
],
Any help would be appreciated!

Answer 1

Okay, so there are two problems with your input. The first is the fact that the given JSON is invalid, so can't directly be parsed. The square brackets after "values" should be curly brackets, to allow for a hash instead of an array:
let raw_old_data =
// Read the old file
fs.readFileSync('./input_data.json').toString()
// Remove all newlines which could interfere with the regex
.replace(/[\r\n]/g, '')
// Replace the square brackets after `"values"` with curly braces
.replace(/"values": \[(.+?)\]/g, '"values": { $1 }');
To convert this (now valid) string to a JSON object, you use JSON.parse:
let old_data = JSON.parse(raw_old_data);
The second problem is that the format in which the values are stored doesn't match your needs. You want to convert from { key: "value" } to [ name: "key", value: "value" ]. The following function can do that, assuming your version of Node supports ES6 (If not, look at Murillo's answer):
function fix_format(obj) {
// This is where we keep the new items in the correct format
let res = [];
// Loop over all values
Object.keys(obj.values).forEach(name => {
let value = obj.values[name];
// Change the format and add to resulting array
res.push({
// If the variable is the same as the key of the hash, it doesn't have to be specified
name,
value,
});
});
return res;
}
All that's then left to do is loop all data from the old object through that function with the Array.map function:
let new_data = old_data.map(fix_format);
And optionally write it back to a file to use with a different program:
fs.writeFileSync('./formatted_data.json', JSON.stringify(data, null, 2));
Note: The 2 in the JSON.stringify function indicates that the resulting JSON should be padded with 2 spaces, to keep it readable.

Answer 2

With ES6:
Object.keys(values).map(name => ({
name,
value: values[name]
}))
Without ES6:
var keys = Object.keys(values);
var newValues = [];
for(var i = 0; i < keys.length; i++){
newValues.push({
name: keys[i],
value: values[keys[i]]
})
}

Answer 3

If your intention is to use the received data i.e obtain data from DB (e.g MSSql, MySql...) using the connection.query(your_custom_sql_query, (err, rows, fields)
for more info:Node.js MySQL Select From Table
I'll recommend you to use:
const myJson = JSON.stringify(rows[0]);