JavaScript provides shorthand operators that combine variable assignment and mathematical operations.
These operators make code more concise and express intent more clearly.
For example, x = x + y can be written as x += y.
This rule applies to the operators +=, -=, *=, /=, %=, **=, <<=, >>=, >>>=, &=, ^=, and |=.
If you need to support environments that do not have all assignment operators, you may need to avoid using some shorthand operators.
You may also prefer the more explicit expanded form if you find it more readable in specific cases.