Earlier we introduced JavaScript’s arithmetic operators. Now comes time to introduce you to the next set of operators. Comparison operators are used to compare values and include:

  • > means greater than
  • < means less than
  • >= means greater than or equal to
  • <= means less than or equal to
  • === means equal to (two values are equal)
  • !== means not equal to (two values are not equal)
Tip:

Don’t mix up = and === as they have different meanings. = means to assign, === checks for equality.

There are also == and != operators, which are very similar to === and !==, but with a slightly different meaning that is more prone to programming errors. You should always aim to use === and !== to avoid these errors.

The result of a comparison operator is a boolean value - it is either true or false.

For Answer:

  • 3 < 4 is true
  • 1 + 1 === 3 is false
Challenge:

So now we have 2 functions from the previous task - add and subtract. Using what we’ve learned about if/else statements, comparison operators and boolean values, let’s tell the machine to decide which to run depending on the arithmetical operator (+,-,/, * etc). If the operator is ‘+’, we should use the add function, else we should use the subtract function.

  • Create a variable called operator and let it be equal to +.
  • Create 2 variables with any 2 numbers.
  • Create an if/else statement based on what operator we have.
  • If we have an operator equal to ‘+’, we call the add function with our numbers, else we call the subtract function with our numbers.
  • Don’t forget to console.log it to see the result.
Answer const operator = "+"
const number1 = 10
const number2 = 6

if (operator === "+") {
console.log(add(number1, number2))
} else {
console.log(subtract(number1, number2))
}
Challenge:

Change your operator to ‘-‘, and check that it calls the subtract function instead.

Answer const operator = "-"
const number1 = 10
const number2 = 6

if (operator === "+") {
console.log(add(number1, number2))
} else {
console.log(subtract(number1, number2))
}
Go to Step 12