Hello everybody!
I'm learning Java programming and have a really, really dumb question to ask.
When writing a line with a counter, such as:
for (var count = 0; count < aString.length; count ++)
what does the ++ do? I've seen it in lots of code and it is mentioned in my book, but what does it actually do?
Cheers!
It's called "incrementation." It's something that has been in programming for a very long time. Even as low level as assembly language, has a special opcode for incrementing variables (INC in asm). This is the process of simply adding one. So, if the value of count is 1, then after the count++ the variable count becomes 2. Higher level languages, such as BASIC (in all forms that I know of) do not use this method. You have to explicitly say: count = count + 1. Also, WHERE you put the ++ becomes important in some languages also. If you put the ++ after (count++) the variable name, then it adds 1 to the variable AFTER whatever condition is tested. If you were to put ++ BEFORE the variable (++count) then it would increment (add one) to the variable BEFORE the condition is tested. Hope that wild explanation has helped a little.
It's called "incrementation." It's something that has been in programming for a very long time. Even as low level as assembly language, has a special opcode for incrementing variables (INC in asm). This is the process of simply adding one. So, if the value of count is 1, then after the count++ the variable count becomes 2. Higher level languages, such as BASIC (in all forms that I know of) do not use this method. You have to explicitly say: count = count + 1. Also, WHERE you put the ++ becomes important in some languages also. If you put the ++ after (count++) the variable name, then it adds 1 to the variable AFTER whatever condition is tested. If you were to put ++ BEFORE the variable (++count) then it would increment (add one) to the variable BEFORE the condition is tested. Hope that wild explanation has helped a little.
This helps a lot, thanks. Just to maintain the dumb question ideal, can I use count = count + 1, and it does the same job?
Cheers!
The Simple Answer: Yes.
for (i=0; i<100; i = i +1) {
document.writeln(i + "<BR>");
}Works (tested in firefox) just fine. The thing with that though... is that if you are concerned about programming speed and power, using var = var + 1 is NOT the way to go. As a matter of programming ethics, and as a matter code effeciency (on a very low level, it takes more time to process i = i + 1, than it does to process i++, but even at a low level, a bunch of i = i + 1's can add up). The best way to add one to a variable is to use ++. The only reason you shouldn't use ++, is if the programming language you are using doesn't support it (like visual basic).
We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.