Processing 1.0 - Processing Discourse - Text input

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Index › Programming Questions & Help › Syntax Questions › Text input - Numbers only

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Text input - Numbers only (Read 994 times)

Terry_Bell YaBB Newbies Offline Posts: 31	Text input - Numbers only Dec 23^rd, 2009, 5:23am I'm want to prompt the user for text input, but only accept numbers and ignore everything else. Other than using 10 if statements, is there a quicker way of doing this? Thanks, TB

JR Full Member Offline Posts: 149	Re: Text input - Numbers only Reply #1 - Dec 23^rd, 2009, 5:26am Integers or decimals?

Terry_Bell YaBB Newbies Offline Posts: 31	Re: Text input - Numbers only Reply #2 - Dec 23^rd, 2009, 5:27am integers - to be more precise if it helps: i want each key press to be added to an array

Quark

Re: Text input - Numbers only
Reply #3 - Dec 23^rd, 2009, 6:21am

The following code will differentiate between digit (0-9) and all other key presses.

Code:

int n;

void draw() { } // Empty draw() needed to keep the program running

void keyPressed() {
  // get the value of the key pressed
  n = int(key);  // int('0') = 48
  n = n - 48;
  if(n >= 0 && n <= 9){
    println("Valid digit: " + n);
  }
  else {
    println("Invalid you pressed " + key);
  }
}

Hope it helps.

subpixel

Re: Text input - Numbers only
Reply #4 - Dec 23^rd, 2009, 6:26am

Terry_Bell wrote on Dec 23^rd, 2009, 5:27am:

integers -

to be more precise if it helps:

i want each key press to be added to an array

More precise is required, not just helpful!

Consider:

Code:

switch (key)
{
  case '0':
  case '1':
  case '2':
  case '3':
  case '4':
  case '5':
  case '6':
  case '7':
  case '8':
  case '9':
    // do something
    break;
  default:
    // do something else
}

or

Code:

if ('0' <= key && key <= '9')
{
  // do something
}
else
{
  // do something else
}

In the "do something" part, you might like to do something starting like so:

Code:

int digit = key - '0';

Since it is still unclear what you mean for a sequence of digits entered (are they to be combined into a single integer, or a simple sequence of one-digit values?), I leave it up to you to figure out what to do next.

-spxl

Processing: subpixels.com, OpenProcessing.org | VJ portfolio: SPXL.TV

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