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Lodash _.keys

Overview

Overview

_.keys is a method provided by the Lodash library that returns an array of keys in an object. It is an easy way to extract keys from an object and use them for different purposes. It is a widely used method and is compatible with all modern browsers and Node.js environments. In this article, we will go through the syntax, usage, and examples of the _.keys method.

Syntax

Here's the basic syntax of the _.keys method:

_.keys(obj)

where obj is the object for which you want to extract the keys.

Usage

The _.keys method returns an array of keys in the object passed as a parameter. The keys are not guaranteed to be in any particular order, but the order is consistent across all environments. The _.keys method is useful when you need to iterate over an object's properties or when you need to extract specific properties from an object. The _.keys method is an alternative to the for...in loop used to iterate over an object's keys.

Examples

Here are some examples that illustrate the use of _.keys method:

Example 1: Extract all keys of an object

var obj = {a: 1, b: 2, c: 3}; var keys = _.keys(obj); console.log(keys); // Output: ["a", "b", "c"]

In this example, we have an object "obj" with three properties "a", "b", and "c". We call the _.keys method on this object, which returns an array containing all the keys of the object.

Example 2: Extract keys with a specific value

var obj = {a: 1, b: 2, c: 2}; var keys = _.keys(obj).filter(function(key) { return obj[key] == 2;}); console.log(keys); // Output: ["b", "c"]

In this example, we have an object "obj" with three properties "a", "b", and "c". We want to extract keys with a specific value, in this case 2. We call the _.keys method on the object, which returns an array containing all the keys of the object. We then use the filter method to extract the keys with value 2.

Example 3: Iterate over an object

var obj = {a: 1, b: 2, c: 3}; _.keys(obj).forEach(function(key) {console.log(key);});

In this example, we have an object "obj" with three properties "a", "b", and "c". We call the _.keys method on this object, which returns an array containing all the keys of the object. We then use the forEach method to iterate over each key of the object and print it to the console.

Conclusion

The _.keys method is a useful method to extract all the keys or specific keys from an object. It provides an easy and efficient way to iterate over an object's properties. Hopefully, this article has provided you with a good understanding of the _.keys method, its syntax, usage, and examples.