Sometimes, we need to adjust the value of a variable.
Imagine we’re working at a bake sale and want to keep track of how many cupcakes we have by creating a variable called numCupcakes:
If we baked 8 more cupcakes, we know that we could update our variable using the + operator:
While this method works just fine, we had to write our variable numCupcakes twice. We can shorten this syntax by using a compound assignment operator.
Compound assignment operators perform an arithmetic operation on a variable and then reassigns its value. Using the += compound assignment operator, we can rewrite our previous code like so:
Now we only need to reference numCupcakes once.
We can use compound assignment operators for all of the arithmetic operators we’ve covered:
- Addition (
+=) - Subtraction (
-=) - Multiplication (
*=) - Division (
/=) - Modulo (
%=)
Instructions
You are also in charge of keeping track of how many cookies there are at the bake sale. This value is represented by the variable numCookies.
A customer comes and buys 3 cookies. Use the appropriate compound assignment operator to reflect this change.
Another customer buys half of the remaining cookies.
Use the appropriate compound assignment operator to reflect this change.