What is the _.pairs() method in underscore.js?

Overview

With the underscore.js node module, we can manipulate arrays and objects with simple functions. The pairs() method converts an object to a single array containing key-value pairs. These key-value pairs will be in the form of arrays.

Syntax

Here's the syntax for underscore.js:

_.pairs(object)
The syntax for the pairs() method using underscore.js

Parameters

object: This is the object we want to convert.

Return value

The value returned is an array. This array will contain key-value pairs in the form of an array, which are the properties and values of the object.

Example

// require underscore
const _ = require("underscore")
// create some objects
let obj1 = {one: 1, two: 2, three: 3, four: 4}
let obj2 = {name: "nodejs", package: "underscore", tag: "_"}
let obj3 = {a: "Apple", b: "Banana"}
let obj4 = {M: "Monday", T: "Tuesday", W: "Wednesday"}
// convert the objects using pairs() method
let arr1 = _.pairs(obj1)
let arr2 = _.pairs(obj2)
let arr3 = _.pairs(obj3)
let arr4 = _.pairs(obj4)
// print the results
console.log(arr1)
console.log(arr2) 
console.log(arr3) 
console.log(arr4)

Explanation

  • Line 2: We require the underscore module.
  • Lines 5–8: We create some objects.
  • Lines 11–14: We convert each object using the pairs() method and save the results.
  • Lines 17–20: We print the results to the console.

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