6.2.1. Variable declaration & initialization
// this is a comment in JS.
// Write your code below this
var who='World';
6.2.2. Changing variable values
// write your code below this line
let greeting = oldGreeting;
greetingLength= greeting.length;
6.2.3. Unchanging variables
// 2 initialized variables
let v3 = 'Hello', v4 = 'World';
// this is a constant declaration
const SPACE = ' ';
// this is a constant variable declaration
// since it is a constant it cannot be assigned later
// it must be initialized on declarations.
// otherwise this causes an error
// merging the two lines below into a
// single declaration with initializer will solve the issue.
let greeting;
greeting = v3 + SPACE + v4;
6.2.4. Types in JS
(c) let v1 = -1.23, v2 = 'Hello';
v1 = v2 + ' world';
6.2.5. Primitive values in JS
(b) If ** is the exponentiation operator, the following code results in n being valued Infinity:
let n = 2 ** 2000;
6.2.6. Number literals
let c = 0x11;
const d = c - 1;
// value of d is 16 in decimal
6.2.7. String literals
// 3 variables
let v1, v2, v3;
// assigning string literal values to the variables
// this has an error. fix by escaping the single-quote
// or by wrapping in double-quotes instead of single-quotes
v1 = "This is Raj\'s desk";
// this has an error. fix by representing the newline using \n
// or by using a template literal
v2 = `Line 1
Line 2`;
// this is assigning a template literal with string interpolation
// there's no error here. don't change this
v3 = `${v1}. You can stand in:
${v2}`;
6.2.8. Array literals
// 3 variables
let v1, v2, v3;
// assigning the second element of arr to v1. don't change this
v1 = arr[1];
// fix below line by changing value of third element of arr to the number 10
arr[2] = 10;
// assign the the sum of first & third elements of arr to v2 & fix error in below line
v2 = arr[0] + arr[2];
// there is no error here. do not change the below line
v3 = `${v2} is ${arr[0] + arr[2]}`;
