Get Keys From Objects in Javascript By Its Value

const obj = { a: 1, b: 2, c: 1, d: 3 };
const valueToFind = 1;

const keysWithValue = Object.keys(obj).filter(key => obj[key] === valueToFind);
console.log(keysWithValue); // Output: ['a', 'c']

const obj = { x: 10, y: 20, z: 10 };
const valueToFind = 10;
const keysWithValue = [];

for (const key in obj) {
  if (obj[key] === valueToFind) {
    keysWithValue.push(key);
  }
}
console.log(keysWithValue); // Output: ['x', 'z']

const obj = { name: 'Alice', age: 25, city: 'Wonderland', hobby: 'Alice' };
const valueToFind = 'Alice';

const keysWithValue = Object.entries(obj)
  .filter(([key, value]) => value === valueToFind)
  .map(([key]) => key);

console.log(keysWithValue); // Output: ['name', 'hobby']

const obj =

The following methods are used to get the key to the value using JavaScript functions.

- Using a for-in loop

- Using the find Method()

- Using filter() Method and Object keys() Method

- Using Object.entries() and reduce() Method

- Using Object.entries() and map() Method

- Using Lodash _.findKey() Method

## Using a for-in loop

It enables the identification of an object's values by iterating through its properties multiple times. You can confirm that the values are accessible for their respective attributes. A for loop is utilized to iterate over the object to obtain its properties.

Following that, the hasOwnProperty() method of the object is utilized to determine if properties are direct or inherited. Subsequently, each property is examined to see if it matches the desired value. If there is a match, the property will be returned. The value of the object can be located in this manner.

### Examples:

The subsequent examples illustrate the significance of the value along with the accessibility of the keys associated with the necessary values.

Example 1

The subsequent example demonstrates the utilization of the "for-in" loop to retrieve the keys associated with values in JavaScript.

Output

The output displays the keys associated with the value in JavaScript.

[image]

Example 2:

The subsequent illustration demonstrates the use of the "for-in" loop to determine the existence of keys and values within JavaScript.

Output

The output displays the keys associated with the value in JavaScript.

[image]

## Using the find Method()

Utilize the Object.keys() function to retrieve an array containing the keys of each object. The find() method is employed to ascertain if any of the keys within this array correspond to the provided value.

The find() method returns the first element that satisfies the specified testing criteria. If the value meets the required conditions, the corresponding key is returned. You can retrieve the value of the item through this method.

### Examples

The example below demonstrates the utilization of the "find" loop to retrieve the keys corresponding to certain values in JavaScript. By employing this technique, we can identify the keys that correspond to the specified values.

Example 1:

The example below demonstrates the use of the "find" loop to retrieve key values in JavaScript.

Output

The output displays the keys associated with the value in JavaScript.

[image]

Example 2:

The subsequent example demonstrates the utilization of the "find" loop to retrieve key values in JavaScript. The key representing unavailable values displays an output of undefined. Conversely, the key associated with multiple values provides the first key as its output.

Output

The output displays the keys associated with the value in JavaScript.

[image]

## Using filter() Method and Object keys() Method

This approach will obtain a key in JavaScript corresponding to its value by employing the object.keys method along with the filter() function.

Should the designated values be present within the object, we have the ability to filter it and retrieve its keys. Conversely, if these values are absent from the object, we can apply filtering and return an empty string.

### Examples

The subsequent illustration demonstrates the utilization of the filter() Method alongside the Object keys() Method in JavaScript to retrieve the keys corresponding to the values. This approach allows us to obtain keys for multiple values, while also returning an empty string for any data that is not available.

Example 1:

The example below demonstrates the utilization of the filter() method in conjunction with the Object keys() method to retrieve the keys corresponding to the available and individual values in JavaScript.

Output

The output displays the keys corresponding to the value in JavaScript.

[image]

Example 2:

The subsequent illustration demonstrates the utilization of the filter() method along with the Object.keys() method to retrieve the keys associated with values that are either absent or duplicated in JavaScript. The keys for absent values will yield an empty output, whereas the keys for duplicated values will present all corresponding keys as output.

Output

The result displays the keys associated with the value in JavaScript.

[image]

## Using Object.entries() and reduce() Method

This approach will obtain a key in JavaScript corresponding to its value by utilizing the Object.entries() method alongside the reduce() function.

### Examples

The subsequent example demonstrates the utilization of the Object.entries() method in conjunction with the reduce() function to extract key values in JavaScript.

Example1:

The subsequent example demonstrates the use of the Object.entries() method in conjunction with reduce() to identify the keys associated with the existing values in JavaScript.

Output

The output displays the keys associated with the value in JavaScript.

[image]

Example 2:

The subsequent illustration demonstrates the utilization of the Object.entries() method in conjunction with the reduce() function to identify the key associated with missing and duplicated values in JavaScript. It is important to note that the case-sensitive nature of the data affects the ability to process the values and retrieve the corresponding keys.

Output

The output displays the keys associated with the value in JavaScript.

[image]

## Using Object.entries() and map() Method

JavaScript employs the Object.entries() method in conjunction with the map() function to retrieve the keys associated with the values. This approach allows us to access all keys, values, and entries, whether they are singular or duplicated, within a hash set.

### Examples

The subsequent illustration demonstrates the utilization of the Object.entries() method in conjunction with the map() function to extract key-value pairs in JavaScript.

Example 1:

The subsequent example illustrates two different approaches to utilizing the Object.entries() and map() methods. The initial approach retrieves all the keys corresponding to the values present in the object through a JavaScript function.

Output

The result displays the keys, values, and entries within JavaScript.

[image]

Example 2:

The subsequent illustration demonstrates the utilization of the Object.entries() method along with the map() function to retrieve the keys corresponding to the existing values in JavaScript, even when multiple values are present.

Output

The output displays the keys, values, and entries within JavaScript.

[image]

Example 3:

The subsequent example demonstrates the utilization of the Object.entries() method in conjunction with the map() function to retrieve the keys associated with values that are both unavailable and case-sensitive in JavaScript.

Output

The output displays the keys, values, and entries within JavaScript.

[image]

## Using Lodash _.findKey() Method

The JavaScript function utilizes the findKey() method from the Lodash library. In this instance, we can employ either an online code editor or the command prompt alongside the Lodash package.

### Example

The subsequent illustration demonstrates the utilization of the Lodash _.findKey() Method to retrieve the key associated with specific values in JavaScript. We employ the Lodash online editors to generate the output. Additionally, Lodash can execute JavaScript code via the command line interface.

Output

The output displays the keys, values, and entries associated with JavaScript.

[image]

## Conclusion

JavaScript provides various functions and methods for retrieving the keys associated with values. We can obtain both individual and multiple values from a hash, but these values remain consistent.