What are the differences between Object.keys() and Object.values() in JavaScript?Gable E
In JavaScript, bothObject.keys()
andObject.values()
are methods used to extract information from an object. They provide different perspectives on the object's properties. Here's a detailed explanation of their differences:
1.Object.keys()
:
- Returns an array of the object's enumerable property names.
- Iterates over the object's own properties, excluding inherited properties.
- The order of the property names in the array is determined by the order in which they were defined or added to the object.
- Example usage:
1 2 3 4
const obj = { a: 1, b: 2, c: 3 }; const keys = Object.keys(obj);
2.Object.values()
:
- Returns an array of the object's enumerable property values.
- Iterates over the object's own properties, excluding inherited properties.
- The order of the property values in the array corresponds to the order of the property names obtained fromObject.keys()
.
- Example usage:
1 2 3 4
const obj = { a: 1, b: 2, c: 3 }; const values = Object.values(obj);
3. Iteration and Mapping:
- Both methods provide convenient ways to iterate over an object's properties or perform operations on them.
- You can use techniques such as array iteration methods (forEach,map
, etc.) on the resulting arrays fromObject.keys()
andObject.values()
to perform operations on the object's properties.
4. Compatibility and Polyfills:
-Object.keys()
andObject.values()
are supported in modern JavaScript environments.
- If you need to support older environments, consider using polyfills or alternative approaches.
5. Usage Considerations:
-Object.keys()
is often used when you need to iterate over an object's properties, access or manipulate the property names, or perform operations that involve only the keys.
-Object.values()
is used when you are interested in the property values and want to perform operations that involve only the values.
6. Object.entries():
- An additional method,Object.entries()
, returns an array of both property names and their corresponding values in the form of key-value pairs.
Choose the appropriate method based on the specific use case and the information you need to extract from the object. In some scenarios, you may even combine these methods to achieve the desired result.
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