Simple snippets for beginners in Javascript

beginner_snippets_javascript.js

// the below are snippets in JavaScript
// they are independent and have been broken
// into smaller functions
// it is likely you'll use them in your code
//
// Remember: no matter how small or big a project maybe
// it still comprises of one or more pieces coming together
// it is just how you use it (LOGIC) to solve a problem.
//
// Arrays & Objects powers the world
// the search results on Google, the list posts on instagram are all Arrays
// no magic about all these data.

function declare_const_let() {
  const a = 1;
  let b = 'Seun';
}

function output_print_statement() {
  console.log('Can you see me?');
}

function output_print_statement_with_special_string() {
  // notice how we use the ` sign rather than ''
  // this means special string formatting
  const myName = 'Seun';

  // the ${} is used for formatting the variable
  // to be passed between the `
  console.log(`Can you see me ${myName}?`);

  // another example:
  const friends = ['Seyi', 'Joy'];
  console.log(`I have ${friends.length} friends`);
}

// ARRAY:

function declare_an_empty_array() {
  const a = [];
}

function declare_an_non_empty_array() {
  const a = ['NG', 'UK', 'US'];
}

function get_the_length_of_array() {
  const a = ['NG', 'UK', 'US'];
  return a.length;
}

function return_elements_in_array() {
  const a = [];
  a.forEach(function (item) {
    // loop through the array
    console.log(item); // every loop should output an item
  });
}

function add_items_to_array() {
  const a = [];
  a.push('James'); // single add
  a.push('Emmy', 'Bola', 'Kola'); // add multiple at once
}

function add_items_to_array_using_loop() {
  const a = [];
  a.forEach(function (item) {
    // loop through the array
    a.push(item); // every loop should 'push'/add an item to it
  });
}

// RELATIVE LOGIC

// boolean
console.log(true === true);
console.log(true === false);
console.log(false === false);

// others
console.log(1 > 2);
console.log(1 > 2);
console.log('Dolapo' === 'Dolapo');

// CONDITIONALS
function is_the_light_on() {
  let status_of_light = true;
  if (status_of_light) {
    console.log('The light is on');
  } else {
    console.log('The light is off');
  }
}

// can be re-written as
function is_the_light_on_2() {
  let status_of_light = true;
  if (!status_of_light) {
    console.log('The light is off');
  } else {
    console.log('The light is on');
  }
}

function is_x_older_than_y(x, y) {
  // now you can see how we use comparison logic here
  // remember: small pieces form bigger solutions
  if (x > y) {
    console.log('x is older sibling');
  } else if (y > x) {
    console.log('y is older sibling');
  }
}

// you can also use if/else
function is_x_older_than_y(x, y) {
  if (x > y) {
    console.log('x is older sibling');
  } else {
    console.log('y is older sibling');
  }
}

// FUNCTIONS

function accountBalance() {
// parameters here
  // function body
  // this is where logic stays
  // you can out put directly using console.log()
  // OR you can just use 'return' statement
}

function accountBalanceA() {
  return 100;
}

// don't forget to initiate your function
accountBalance();

// sometime you want to print the value
console.log(accountBalance());

// OR you may want to use it somewhere else

const withdrawalAmount = 100;

function withdrawalMoney(amount) {
  return accountBalanceA() - amount;
}

withdrawalMoney(withdrawalAmount);

// Bonus:
// Functions can be rewritten using arrow functions
// they look like this '() =>'
//
// i.e
//
// function accountBalance() {
//  return 100;
// }
//
// BECOMES
//
// const accountBalance = () => {
//  return 100;
// }
//
// AND
//
// function withdrawalMoney(amount){}
//
// BECOMES
//
// const withdrawalMoney = (amount) => {}
//
// Don't worry, you don't have to bother too much
// as you practice you'll get used to it :)
//
// just putting it here
// in case you come across it in other people's project ;)

// examples where arrow functions are also used
a.forEach((item) => {});
a.map((item) => {});