if (condition_1) {
  statement_1;
} else if (condition_2) {
  statement_2;
} else if (condition_n) {
  statement_n;
} else {
  statement_last;
} 
//To execute multiple statements, group them within a block statement
if (condition) {
  statement_1_runs_if_condition_is_true;
  statement_2_runs_if_condition_is_true;
} else {
  statement_3_runs_if_condition_is_false;
  statement_4_runs_if_condition_is_false;
}

let theNumber = Number(prompt("Pick a number"));
if (!Number.isNaN(theNumber)) {
  console.log("Your number is the square root of " +
              theNumber * theNumber);
}else{
  console.log('Your input is not a number');
}

fruitType='Apples';
switch (fruitType) {
  case 'Oranges':
    console.log('Oranges are $0.59 a kilo.');
    break;
  case 'Apples':
    console.log('Apples are $0.32 a kilo.');
    break;
  case 'Bananas':
    console.log('Bananas are $0.48 a kilo.');
    break;
  default:
   console.log('Sorry, we are out of ' + fruitType + '.');
}
console.log("Is there anything else you'd like?");