Sometimes, we want to add a new key value pair in existing JSON object using JavaScript.
In this article, we’ll look at how to add a new key value pair in existing JSON object using JavaScript.
How to add a new key value pair in existing JSON object using JavaScript?
To add a new key value pair in existing JSON object using JavaScript, we can parse the JSON string with JSON.parse, then add the key-value pairs we want, and then convert the object back to a JSON string with JSON.stringify.
For instance, we write:
const s = `{
"workbookInformation": {
"version": "9.1",
"source-platform": "win"
},
"datasources1": {
},
"datasources2": {
}
}`
const obj = JSON.parse(s)
obj.foo = 'bar'
const newS = JSON.stringify(obj)
console.log(newS)
to parse s into an object with JSON.parse.
Then add the foo property to obj.
And then we call JSON.stringify with obj to convert it back to a JSON string.
Therefore, newS is {"workbookInformation":{"version":"9.1","source-platform":"win"},"datasources1":{},"datasources2":{},"foo":"bar"}.
Conclusion
To add a new key value pair in existing JSON object using JavaScript, we can parse the JSON string with JSON.parse, then add the key-value pairs we want, and then convert the object back to a JSON string with JSON.stringify.
