Underscore.js _.takeSkipping() Method

The _.takeSkipping() method takes an array and a skip value (say n) and creates an array containing every nth element of the original array.

For an index >= 0 first element of the new array is always the same as the first element of the original array.

Syntax:

_.takeSkipping(array, skip_value)

Parameters:

• array: The array from which skip array is to be made.
• skip_value: The value which is used to make skip array from original array.

Return Value: This method returns a newly created skip array.

Note: This will not work in normal JavaScript because it requires the underscore.js contrib library to be installed. Underscore.js contrib library can be installed using npm install underscore-contrib –save.

Example 1: In this example, we will generate a skip array using this method.

Javascript

// Defining underscore contrib variable

var _ = require('underscore-contrib');
// Array

var array = [1, 2, 3, 4, 6, 4, 3, 10];

// skipValue
var skip = 2;

// Generating Array using takeSkipping() method
var arr =_.takeSkipping(array, skip);
console.log("Array : ", array);
console.log("Skip Value : ", skip);
console.log("Generated Array : ", arr);

Output: generated skip array contains the (n+2)th indexed element.

Array :  [
  1, 2, 3, 4,
  6, 4, 3, 10
]
Skip Value :  2
Generated Array :  [ 1, 3, 6, 3 ]

Example 2: This method is safe for skip values greater or lesser than the array size.

Javascript

// Defining underscore contrib variable
var _ = require('underscore-contrib');

// Array
var array = [1, 2, 3, 4, 6, 4, 3, 10];

// skipValue
var skip = 20;

// Generating Array using takeSkipping() method
var arr =_.takeSkipping(array, skip);
console.log("Array : ", array);
console.log("Skip Value : ", skip);
console.log("Generated Array : ", arr);

Output: Only first element or 0th indexed element is in the generated array.

Array :  [
  1, 2, 3, 4,
  6, 4, 3, 10
]
Skip Value :  2
0
Generated Array :  [ 1 ]

Example 3: For negative skip value it returns an empty array.

Javascript

// Defining underscore contrib variable
var _ = require('underscore-contrib');

// Array
var array = [1, 2, 3, 4, 6, 4, 3, 10];

// skipValue
var skip = -20;

// Generating Array using takeSkipping() method
var arr =_.takeSkipping(array, skip);
console.log("Array : ", array);
console.log("Skip Value : ", skip);
console.log("Generated Array : ", arr);

Output:

Array :  [
  1, 2, 3, 4,
  6, 4, 3, 10
]
Skip Value :  -20
0
Generated Array :  []