Javascript Functions Development Tutorials, Guides & Insights

• Arrow Functions (ES6):

  const multiply = (a, b) => a * b;
  console.log(multiply(4, 7)); // 28

Variables are used to store data that can be reused throughout your code. In JavaScript, you can declare variables using var, let, or const.

let name = "Alice";
const age = 25;
var isStudent = true;

console.log(name, age, isStudent);

However, there are situations where you might want to control or change the value of this, and that's where call, apply, and bind come into play.

The call method allows you to invoke a function with a specified this value and arguments passed individually.

Underscore.js is a lightweight utility library similar to Lodash, providing useful functions for working with arrays, objects, and other data types.

<table>
  <tr>
    <th>Function</th>
    <th>Description</th>
    <th>Example</th>
  </tr>
  <tr>
    <td><code>_.each(list, iteratee)
    Iterates over a list, invoking the iteratee for each element.
    _.each([1, 2, 3], alert)
  
  
    _.map(list, iteratee)
    Creates a new array by applying the iteratee to each element in the list.
    _.map([1, 2, 3], num => num * 3) => [3, 6, 9]
  
  
    _.reduce(list, iteratee, memo)
    Reduces a list to a single value by iterating and combining elements.
    _.reduce([1, 2, 3], (sum, num) => sum + num, 0) => 6
  
  
    _.filter(list, predicate)
    Returns an array of elements that pass a truth test.
    _.filter([1, 2, 3, 4], num => num % 2 == 0) => [2, 4]
  
  
    _.findWhere(list, properties)
    Returns the first element that matches the specified properties.
    _.findWhere([{a: 1}, {a: 2}], {a: 2}) => {a: 2}