The double-selection structure (if...else)

The following code snippet declares a variable of type boolean and name isValid. Then, an if statement will check whether the value of isValid is equal to true. If the statement turns out to be true, the message Is valid! will be displayed on the screen. On the other hand, if the statement turns out to be false, the message Is NOT valid! will be displayed on the screen:

let isValid: boolean = true; 
 
if (isValid) { 
  console.log("Is valid!"); 
} else { 
  console.log("Is NOT valid!"); 
}