conditional-statements.md

Conditional statements

Computers only function by logical rules: whether something is true or not determines if an instructions gets executed or not. This logical process is expressed in a conditional statement and goes like this: if this is the case, then that happens. Or in code:

if (/* this is the case */) {
  // then this will happen
}

A condition is put in the ( ) and it needs to evaluate to true or false (also known as Boolean values). If the condition is true, then whatever is inside the { } will be executed.

What happens when the condition is false? For that we have the else { } block. If the condition is false, then whatever is inside the else will be executed:

if() {

} else {

}

The following video shows different ways of telling JavaScript to go in a different direction:

{% hyf-youtube src="https://www.youtube.com/watch?v=nBj2nJup8xU" %}

Ternary operator

Sometimes the condition is very small and having the whole if/else structure would make the code more complex. If that is the case then you can make use of the ternary operator. Have a look at the following example:

// If/else way
const age = 43;

if (age > 18) {
  console.log('Yes you may vote');
} else {
  console.log('You may not vote yet');
}

// Ternary way
console.log(age > 18 ? 'Yes you may vote' : 'You may not vote yet');

Whenever you are deciding which way to use, only think about the readability of the code. In terms of the compiler these things are exactly the same.

Extra reading

If you just can't get enough, here are some extra links that mentors/students have found useful concerning this topic:

• More about the ternary operator