Everything to the right of the equals sign is evaluated first, so we can say myVar = myVar + 5; to add 5 to myVar. Since this is such a common pattern, there are operators which do both a mathematical operation and assignment in one step.

One such operator is the += operator.

myVar += 5; will add 5 to myVar instead of using any of the follwoing:

myVar = 5 + myVar;
myVar = myvar + 5;