Extract unique values :

let name = [ 'Aditi',  'Ayushi', ' Sanaya',  'Aditi',  'Aditi' ];
let newName = [...new Set(name)];
console.log( newName);       // Output: ["Aditi", "Ayushi", " Sanaya"]

Sum of all numbers in an array

let num = [5, 3, 7, 2, 8,];
num.reduce((a, b) => a+b, 0);  // Output: 25

Generate a random number in a range

Math.floor(Math.random() * 7); // In a range between 0 and 6

Convert string to character

let course = "JavaScript"
let char = [...course];
console.log(char);   // Output:  ["J", "a", "v", "a", "S", "c", "r", "i", "p", "t"]

Destructuring variable

let [aditi, ...name] = [ 'Aditi',  'Ayushi', ' Sanaya', 'Sumit'];
aditi;
name;  
// Output: ["Ayushi", " Sanaya", "Sumit"]

Merging arrays

let name = [ "Aditi", "Ayushi", " Sanaya", "Sumit" ]
let Course = ["JavaScript", "React", "NodeJs"];
let nameAndCourse = [...name, ...Course];
console.log(nameAndCourse);

// Output:  ["Aditi", "Ayushi", " Sanaya", "Sumit", "JavaScript", "React", "NodeJs"]

Convert to string

let num = 7 + " ";

console.log(num);  // Output: 7
console.log(typeof num) // Output: "string"

Convert to number

let num = "8";
num = +num;

console.log(num);  // Output: 8
console.log(typeof num) // Output: number

Resizing array

let num = [ 1, 2, 3, 4, 5 ];
array.length = 3;
console.log(array);  // Output: [1, 2, 3]

Log values with variable names

let newCourses = "JavaScript";
console.log({ newCourses });  // Output: {newCourses: "JavaScript"}