Essential JavaScript

Increment / Decrement

Earlier, we covered shorthand math operators.

This is what shorthand addition and subtraction look like:

let count = 0;
count += 1;
console.log(count);

let retries = 3;
retries -= 1;
console.log(retries);

For the addition example, notice how we are only adding 1 to the value of the variable.

Adding and subtracting 1 is a very common operation in programming. To make it easier, we have special shorthand operators to add and subtract 1.

Increment and Decrement Operators

To add 1 to a variable, we use the increment operator, which is a double plus sign: ++

let count = 0;
count++;
console.log(count);

To subtract 1 from a variable, we use the decrement operator, which is a double minus sign: --

let retries = 3;
retries--;
console.log(retries);

Practice

There are several examples in the editor that use the shorthand addition operator to add just 1 to a variable.

Replace them with the increment operator to make the code cleaner.


Learning Goals

Code Editor