Beginner B20 – IF Statements and Booleans
How to use IF / ELSE statements to check the status of variables and booleans to act as a switch.
Code Used (Javascript)
var myCheck : boolean = true;
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function Update () {
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if(myCheck){
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guiText.text = "Its on!";
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}else{
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guiText.text = "Its Off!";
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}
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if(Input.GetButtonUp("Jump") && myCheck){
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myCheck = false;
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}else if(Input.GetButtonUp("Jump") && myCheck == false){
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myCheck = true;
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}
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}
Further Reading
19 Comments
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If you’re even lazier you could also write
if (Input.GetButtonUp (“Jump”)) {
myCheck = !myCheck;
}
..but maybe you wanted to show an example of an else-if statement
Do you think you could explain what myCheck=!myCheck means for all of us noobs?
tommy – when you use != it means ‘does not equal’, so setting something to what it does not equal, in the instance of a boolean (true / false) variable, would set it to its opposite value. make sense?
Guess this is kinda late, but well…
@tommy:
myCheck = !myCheck; (regard the space between the “=” and “!”)
That line sets the boolean myCheck to its opposite state.
The “!” in front of a boolean is similiar to a “not” (not true ends in false, not false ends in true – guess its obvious, but just making sure).
Thus a few lines and conditions aren’t necessary anymore.
@wgstone
You obviously are right about the “!=” being the opposite of “==”, but the original line of code doesn’t include either. He just skipped all spaces making everything a little messier^^
Thanks Marcus! I’m always happy to be lazy!
Untested but it would be more simple to write the code like this.
seriously, less lines do make a difference especially when debugging or changing code
var myCheck : boolean = true;
function Update () {
guiText.text = myCheck? “Its on!”: “Its Off!”;
myCheck = GetButtonUp(“Jump”) && myCheck ==false
}
Not really, you can’t use ? in this context, but I totally agree that the simpler, and more efficient, the better of course – some of the examples on the site, especially in beginner terms are aimed at fostering understanding of the concepts rather than most efficient practice.
@wgstone:
guiText.text = myCheck ? “Its on!” : “Its Off!”;
I just quickly tested it and as i thought, it does work, even if I agree with you on it being less likely understood^^
myCheck = GetButtonUp(“Jump”) && myCheck == false
Whereas this DOESN’T work.
If you want a shorter version, the code below does work:
———————————————————————–
var myCheck : boolean = true;
function Update ()
{
guiText.text = myCheck ? “Its On!” : “Its Off!”;
if(Input.GetButtonUp(“Jump”)) myCheck = !myCheck;
}
———————————————————————–
The “?” checks the state of the boolean to the far left. If it’s true it sets it to the value left of the “:”, if it’s false to the one on the right (It works pretty much the same like an if-else-statement).
Ok but note that the one you quote that ‘DOESN’T’ work, only does not because you have a single ‘=’ in the first comparative myCheck = GetButtonUp(“Jump”) where it should be “==”.
Sorry, me again. I’m really picky, I know.
In you code box under the video, the four ampersands (&) are written as & . I think you’ve got a HTML error there somewhere, or it may be a browser problem (I use FF3.6.13)
Sorry, that should be & is written as & a m p ; without the spaces.
Thanks for the tutorials and quick question here. Is this statement
really more efficient than the standard if-else or is it just more simple for some to write.
guiText.text = myCheck? “Its on!”: “Its Off!”;
can someone tell my why this is only spawning an object once (on the first loop)
var my : boolean = true;
var baddy : GameObject;
function Start() {
if (my) (
Instantiate(baddy, transform.position, transform.rotation));
my = false;
yield WaitForSeconds(.5);
my = true;
}
Because Start() only runs once so it’s not really a loop, make a real for loop in Update() ideally.
Noobs, go to study JavaScript, then return here.
Actually this site is designed to help people learn, not exclude them.
This tutorial should be B00, not B20
.
how do i bin other keys to script. for instance, how can i assign “f” button to switch the text? when i simply insert it instead of “Jump” it says that “f” is not setup or smth… thank you
either change jump to have F as its positive button in input settings – Edit > Project Settings > Input , or use GetKeyCode – see script reference.