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How to increment/decrement a variable by a decimal number?

Discussion in 'Scripting' started by General Jackson, Aug 2, 2011.

  1. General Jackson

    General Jackson

    Joined:
    Oct 31, 2009
    Posts:
    73
    Hi everyone, I have a problem. With this Code:
    Code (csharp):
    1. if (throttle < 0)  
    2.   if(Input.GetKeyDown ("-"))
    3.   throttle++;
    It increments throttle variable by 1. That's great and all. But I need to increment it by 0.1
    How do I go about doing this? I cannot figure it out for the life of me!
    Thanks,

    GJ
     
  2. heathCliff

    heathCliff

    Joined:
    Nov 29, 2010
    Posts:
    5
    Code (csharp):
    1.  
    2. throttle += 0.1;
    3.  
     
  3. HarvesteR

    HarvesteR

    Joined:
    May 22, 2009
    Posts:
    499
    how about:

    throttle += 0.1;

    Cheers

    EDIT: Ninja'd!

    Oh, well...

    Most operators will have a self-incrementing version of themselves actually, as += and -=, you can also use *=, /= and %=

    Cheers
     
  4. eTag96

    eTag96

    Joined:
    Oct 24, 2010
    Posts:
    110
    throttle += 0.1f;
     
  5. U7Games

    U7Games

    Joined:
    May 21, 2011
    Posts:
    943
    negative countdown, why not to use while instead ?.. or may you are using update function btw, i will add a simplest line :

    throttle += .1;

    i can see this is the first post where all are agreed instantly..
     
  6. General Jackson

    General Jackson

    Joined:
    Oct 31, 2009
    Posts:
    73
    Code (csharp):
    1. var throttle = 0;
    2. var increment = 0.1;
    3. function Update () {
    4.  
    5.  
    6.  
    7. if (Input.GetKey ("up"))
    8. transform.Rotate(-1,0,0);
    9.  
    10. if (Input.GetKey ("down"))
    11. transform.Rotate(1,0,0);
    12.  
    13. if (Input.GetKey ("left"))
    14. transform.Rotate(0,0,-1.5);
    15.  
    16. if (Input.GetKey ("right"))
    17. transform.Rotate(0,0,1.5);
    18.  
    19. if (throttle > -4)  
    20.   if(Input.GetKeyDown ("="))
    21.   throttle-= 0.1;
    22.  ;
    23.  
    24.  
    25.  
    26. if (throttle < 0)
    27. transform.Translate(0,0,throttle);
    28.  
    29. }
    That is my entire code.
    The Throttle does not work still.
    What could I be doing wrong?
     
  7. U7Games

    U7Games

    Joined:
    May 21, 2011
    Posts:
    943
    replace from the second "if" to the last one with "else if", because you are identifying the same condition.. maybe is that ...

    note that you have a semicolon after the "throttle-=0.1; line you must to delete it.. ;)
     
    Last edited: Aug 2, 2011
  8. Eric5h5

    Eric5h5

    Volunteer Moderator Moderator

    Joined:
    Jul 19, 2006
    Posts:
    32,250
    You're typing throttle as an int, so you can't add or subtract decimals from it. Also, that code won't work right, because it's framerate-dependent. You need to use Time.deltaTime. Additionally, it would be simpler if you used GetAxis. (If you do use GetKey, it's better to use KeyCodes rather than strings.)

    --Eric
     
  9. General Jackson

    General Jackson

    Joined:
    Oct 31, 2009
    Posts:
    73
    Ok how do I change it to a (float?)? when I put 'float throttle' the other parts of the code didnt work.
    Sorry I am still fairly new to JS,
     
  10. Moonjump

    Moonjump

    Joined:
    Apr 15, 2010
    Posts:
    2,397
    var throttle = 0.0;
     
  11. Eric5h5

    Eric5h5

    Volunteer Moderator Moderator

    Joined:
    Jul 19, 2006
    Posts:
    32,250
    Either "var throttle : float = 0", or "var throttle = 0.0".

    It's not doing anything, so it would be better to delete it, but it's not actually necessary. It's a blank line; I wonder if the compiler actually uses some kind of no-op instruction, or if it's ignored entirely?

    --Eric
     
  12. General Jackson

    General Jackson

    Joined:
    Oct 31, 2009
    Posts:
    73
    That did it! Thanks a million!
     
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