Strings in depth

const name = 'Meena';
const amount = 250;
const msg = `Hi ${name}, you paid Rs ${amount}.`;
const gst = `GST: Rs ${amount * 0.18}`;   // any expression works inside ${}
const receipt = `Order: A101
Items: 3
Total: Rs 750`;                         // keeps the line breaks

const city = 'Bengaluru';
city.length;       // 9
city[0];           // 'B'
city.at(-1);       // 'u'  (a negative number counts from the end)
city.slice(0, 4);  // 'Beng' (from index 0 up to, not including, 4)
city.slice(-3);    // 'uru'  (the last 3 characters)
city.indexOf('g'); // 3

const list = 'rice,dal,oil';
const items = list.split(',');   // ['rice', 'dal', 'oil']
items.join(' | ');               // 'rice | dal | oil'

const words = '  learn   web  dev '.trim().split(' ').filter(Boolean);
// ['learn', 'web', 'dev']  filter(Boolean) drops the empty strings

const slug = 'JavaScript In Depth'.toLowerCase().split(' ').join('-');
// 'javascript-in-depth'

'Pune'.toLowerCase() === 'pune';      // true
['b', 'a', 'C'].sort();               // ['C', 'a', 'b']  capitals first
['b', 'a', 'C'].sort((x, y) => x.localeCompare(y)); // ['a', 'b', 'C']
'apple'.localeCompare('banana');      // a negative number: apple comes first

const inr = new Intl.NumberFormat('en-IN', { style: 'currency', currency: 'INR' });
inr.format(100000);  // '₹1,00,000.00'
inr.format(2499.5);  // '₹2,499.50'

new Intl.NumberFormat('en-IN').format(12345678); // '1,23,45,678'

(199.999).toFixed(2);   // '200.00'  a string with 2 decimals
(0.1 + 0.2).toFixed(2); // '0.30'

let name = 'ravi';
name[0] = 'R';      // does nothing
name.toUpperCase(); // returns 'RAVI', but name is unchanged
console.log(name);  // 'ravi'
name = name[0].toUpperCase() + name.slice(1); // store the new string
console.log(name);  // 'Ravi'