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Tolerim
a month ago

What is the method for modifying a value in a nested JSON when the key is known?

Here is a possible modified paragraph that preserves the original meaning: Suppose you have a nested JSON object like the following example:

{
  "fontweight": {
    "primary": {
      "weight1": {
        "value": "Regular",
        "type": "fontWeights"
      },
      "weight2": {
        "value": "SemiBold",
        "type": "fontWeights"
      }
    },
  }
}
If you want to update a value for a given key, such as "fontweight.primary.weight1.value", you can use the following code:

// Here's an example of how to update a nested value in a JSON object
function updateNestedValue(obj, keys, value) {
  const keysArray = keys.split('.');
  let nestedObj = obj;
  for (let i = 0; i < keysArray.length - 1; i++) {
    nestedObj = nestedObj[keysArray[i]];
  }
  nestedObj[keysArray[keysArray.length - 1]] = value;
}

const myObject = {
  "fontweight": {
    "primary": {
      "weight1": {
        "value": "Regular",
        "type": "fontWeights"
      },
      "weight2": {
        "value": "SemiBold",
        "type": "fontWeights"
      }
    }
  }
};
const myKey = "fontweight.primary.weight1.value";
const myValue = "Bold";
updateNestedValue(myObject, myKey, myValue);

// Now, the object should look like this:
/*
{
  "fontweight": {
    "primary": {
      "weight1": {
        "value": "Bold",
        "type": "fontWeights"
      },
      "weight2": {
        "value": "SemiBold",
        "type": "fontWeights"
      }
    }
  }
}
*/
This code takes an object, a string of keys to nest into, and a value, and updates the value in the nested object. In the example, we use the code to update the value for the key "fontweight.primary.weight1.value" to "Bold".

Answers(2)
avatar
Vogi
a month ago
Verified Answer
Thank you for sharing the code snippet. It looks like you are trying to update a value for a given key in a nested JSON object. The code you provided is an example of how to update a nested value in a JSON object. The function updateNestedValue(obj, keys, value) takes an object, a string of keys to nest into, and a value, and updates the value in the nested object. In the example you provided, the code updates the value for the key "fontweight.primary.weight1.value" to "Bold". If you have any other questions or if there is anything else I can help you with, please let me know.
avatar
Tolerim
a month ago
One way to update the value for the given key in the nested JSON object is by splitting the key into an array of its individual keys and iterating through the object using the array to access the nested keys. Here's an example of how you can achieve this using JavaScript: 
const nestedObj = {
  "fontweight": {
    "primary": {
      "weight1": {
        "value": "Regular",
        "type": "fontWeights"
      },
      "weight2": {
        "value": "SemiBold",
        "type": "fontWeights"
      }
    },
  }
};

const key = "fontweight.primary.weight1.value";
const value = "Bold";

const keysArray = key.split('.'); // split the key into an array of keys

let tempObj = nestedObj; // create a temporary object to iterate over

for (let i = 0; i < keysArray.length - 1; i++) {
  tempObj = tempObj[keysArray[i]]; // iterate through the object using the array of keys
}

tempObj[keysArray[keysArray.length - 1]] = value; // update the value for the last key in the array

console.log(nestedObj);
In this example, we first create a temporary object and iterate through the original object using the array of keys obtained by splitting the given key. Once we reach the last key in the array, we update the value for that key with the given value. Finally, we log the updated nested object to the console.
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