text: 21 == 9+12;
  false != true;
  6 > 1;
  5 >= 5;
  "1" == 1;
  
  if (0) console.log("reached");  // doesn’t succeed
  console.log( 0 == false ); // prints true
  console.log( 0 === false ); // prints false
  
  var falseValue = !true;
  
  if (!!1 === true) {
    console.log("this code will execute");
  }
  
  function logAndReturn( value ) {
    console.log( "logAndReturn: " +value );
    return value;
  }
  if ( logAndReturn (true) || logAndReturn (false)) {
    console.log("|| operator returned truthy.");
  }
  
  // Following two variables are set to "anonymous" (simple) objects,
  // each with two fields, ‘name’ and ‘happy’, set to initial values (both sad)
  var john= {name: "John", happy: false};
  var lucy= {name: "Lucy", happy: false};
  
  function make_happy( person ) {
    console.log("Making " +person.name+ " happy.");
    person.happy= true;
    return true;
  }
  
  if (make_happy(john) || make_happy(lucy)) {
    console.log("John is happy: " +john.happy+ ", Lucy is happy: " +lucy.happy);
  }
  
  ageLimit = ageLimit || 21;
  
  console.log( 1 == true ); // => true, but:
  console.log( 2 == true ); // => false, because true first converts to 1
  console.log( 2 == false ); // => also false, because false converts to 0
  
  console.log( !!2 == true ); // => true
  console.log( !!2 == false ); // => false
  
  console.log( 1 + 2 + 3 ); // => 6
  console.log( true && true && false ); // => false
  
  console.log( 1 < 3 < 2 ); // 1<3 => true, but then: true<2 => 1<2 => true!
  
  console.log( 2==2==2 ); // 2==2 => true, but then: true==2 => 1==2 => false!
  // Similarly with 0:
  console.log( 0==0==0 ); // 0==0 => true, but then: true==0 => 1==0 => false!
  // However, not the same with 1:
  console.log( 1==1==1 ); // 1==1 => true, then: true==1 => 1==1 => true
  
  let age = 22;
  
  var action = (age < 21) ? "Deny access" : "Grant access";
  
  var action;
  if (age < 21) {
    action = "Deny access";
  } else {
    action = "Grant access";
  }
  
  var status = (age < 18) ? "child" : (age > 65) ? "pensioner" : "adult";
  
  var status;
  if (age < 18) {
    status = "child";
  } else if (age > 65) {
    status = "pensioner";
  } else {
    status = "adult";
  }
  
  