Let’s consider how we can use variables and math operators to calculate new values and assign them to a variable. Check out the example below:
let w = 4; w = w + 1; console.log(w); // Output: 5
In the example above, we created the variable w
with the number 4
assigned to it. The following line, w = w + 1
, increases the value of w
from 4
to 5
.
Another way we could have reassigned w
after performing some mathematical operation on it is to use built-in mathematical assignment operators. We could re-write the code above to be:
let w = 4; w += 1; console.log(w); // Output: 5
In the second example, we used the +=
assignment operator to reassign w
. We’re performing the mathematical operation of the first operator +
using the number to the right, then reassigning w
to the computed value.
We also have access to other mathematical assignment operators: -=
, *=
, and /=
which work in a similar fashion.
let x = 20; x -= 5; // Can be written as x = x - 5 console.log(x); // Output: 15 let y = 50; y *= 2; // Can be written as y = y * 2 console.log(y); // Output: 100 let z = 8; z /= 2; // Can be written as z = z / 2 console.log(z); // Output: 4
Let’s practice using these mathematical assignment operators!
Instructions
Use the +=
mathematical assignment operator to increase the value stored in levelUp
by 5
.
Use the -=
mathematical assignment operator to decrease the value stored in powerLevel
by 100
.
Use the *=
mathematical assignment operator to multiply the value stored in multiplyMe
by 11
.
Use the /=
mathematical assignment operator to divide the value stored in quarterMe
by 4
.