Essential JavaScript

Conditionals (else)

When we write a conditional statement, the code inside the curly braces only runs if the condition is true.

But what if the condition is false? We can write code to handle that scenario as well.

Try this code in the editor:

if (true === false) {
  "true is equal to false";
}
else {
  "true is not equal to false";
}

The else keyword can follow up from an if statement and run code if the condition is not met.

Multiple if Conditions

We can actually create a chain of conditions to check. Run this code in the editor:

if (1 > 2) {
  "1 is greater than 2";
}
else if (1 < 2) {
  "1 is less than 2";
}
else {
  "1 is equal to 2";
}

The else if statement can follow up from an if statement, just like a regular else statement can. However, the else if statement has its own condition to check. It will only run if its own condition is true.

Try changing the example to get different sections of code to run.

Conditions in a Function

Let's see what a conditional statement looks like inside a function. Now we have arguments to work with, like input below. input could be any value.

This function will return true if input is either true or false. If input is any other value, false is returned.

Try calling the function with different values to get different results:

function checkIfTrueOrFalse(input) {
  if (input === true) {
    return true;
  }
  else if (input === false) {
    return true;
  }
  else {
    return false;
  }
}
checkIfTrueOrFalse(17);

Learning Goals

Code Editor