Finding a Non-Constant Key in a Nested Object through Recursive Function Calls

Searching for a Specific Key in a Nested Object Using Recursive Function Calls

The code snippet demonstrates a recursive function called findKey that is used to search for a specific key within a nested object. This can be useful when working with dynamic or inconstant objects, where the structure may vary.

Here’s an example of implementation:

findKey = (obj, targetKey) => {
    for (let key in obj) {
        if (key === targetKey) {
            return obj[key];
        }

        if (typeof obj[key] === 'object' && obj[key] !== null) {
            const result = this.findKey(obj[key], targetKey);
            if (result !== undefined) {
                return result;
            }
        }
    }
    return undefined;
}

// Example usage
const obj = {
  a: 1,
  b: {
    c: 2,
    d: {
      e: 3,
      f: {
        g: 4,
      },
    },
  },
};

const targetKey = 'g';
const value = findKey(obj, targetKey);
console.log(value); // Output: 4

The findKey function takes two parameters: obj and targetKey.

• obj represents the object in which you want to search for the key.
• targetKey is the key you want to find within the object.

The function starts by iterating over each key in the obj using a for...in loop. It compares each key with the targetKey.

• If the current key matches the targetKey, the function returns the corresponding value obj[key].
• If the current value of the key is an object (and not null), the function makes a recursive call to findKey, passing in the nested object obj[key] as the new obj parameter. This allows the function to continue searching for the targetKey within nested objects.
• If the targetKey is not found within the current object or any of its nested objects, the function returns undefined.

The example usage section demonstrates how to use the findKey function.

• It defines an example object obj with multiple levels of nesting.
• The targetKey is set to 'g', representing the key we want to find within the object.
• The findKey function is called with obj and targetKey, and the returned value is stored in the value variable.
• Finally, the value variable is printed to the console, which in this case would be 4, as it corresponds to the value associated with the key 'g' within the nested object.

This recursive approach allows you to search for a specific key within nested objects, even when the structure or depth of the object is unknown or subject to change. It provides flexibility and reusability, making it suitable for various scenarios when working with complex and dynamic data structures.