In my last post, I began discussing operators and how we can do basic math (which is most of the math you do in programming). I would like to continue discussing operators today by addressing increment and decrement. There are times in programming where you want to simply add or subtract one from a number. The increment and decrement operators do just that…give or take away just one more. Let’s take a gander at some examples…
[code lang=”js”]
// Create while loop which counts over a variable
// Create count variable
var count = 0;
while(count < 5){
document.writeln(count);
count++;
}
[/code]
Notice the line that displays count++. What this does is add one to the value of count. So the first time this loop runs, the value of count will be zero, the second time it runs, the value will be 1, then 2 and so on until it hits 5 and the loop condition returns false. Write out count++ is equivalent to the following code…
[code lang=”js”]
count = count + 1;
[/code]
As you can see count++ is shorter, thus much quicker to write. Anything that we can do in shorthand is a cost and time savings.
Decrement works in a similar fashion. The difference is that it subtracts one. Let’s alter our previous example…
[code lang=”js”]
// Create while loop which counts over a variable
// Create count variable
var count = 5;
while(count > 0){
document.writeln(count);
count–;
}
[/code]
In practice, you will probably use increment more often than decrement, but it is nice to know how to use both operators.
Happy Coding!
Clay Hess
