Problems with print() function

p5.js Beginners
1

I am new to p5.js and I encountered a problem with a simple code:

var a=10;
var b;
function setup() {
  createCanvas(400, 400);
  //some expressions using variables go here
  
}
function draw() {
  background(220);
  //more expressions using variables go here
  print()
  }

If I add a print() function, before I am able to type in any parameters printer dialog
opens and goes into an infinite loop. No matter I press print or cancel buttons, the dialog comes back.It does not happen all the time. Please advise!

2

I think in p5.js you use console.log() to print statements to the console

1 Like
3

Hi @sirin, and welcome to the Processing Forum!

By default, the draw() function is called repeatedly. Therefore your call to print() occurs within an infinite loop. Add a call to noLoop() within the setup() function to prevent this, as follows:

function setup() {
  createCanvas(400, 400);
  //some expressions using variables go here
  noLoop();
}
4

Thank you, I am aware of that, but according to p5.js reference reference | p5.js, print() also supposed to work. And it works, but not all the times. Is it a bug?

5

Thank you for your comment. The problem is not in print () peritedly working in draw().
The problem is that print() with no arguments specified opens a dialog with my printer before I can add arguments to print().

6

After having stopped all instances of my copy of your program from running in the browser, I was able to add an argument to print(), as follows:

var a=10;
var b;
function setup() {
  createCanvas(400, 400);
  //some expressions using variables go here
  noLoop();
}
function draw() {
  background(220);
  //more expressions using variables go here
  print("Hello, World!");
}

The following was displayed in the JavaScript console when the program was started again:

Hello, World!
1 Like
7

Hey @sirin , I suppose you’re using the p5 web editor with auto refresh enabled. As you mentionned, print aims to open a print dialog if you don’t pass a string or a variable in parameters. So, you can disabled the auto-refresh option while you type your code, give a string in your print() and then enable it again.
Not convenient, I have to admit it.

1 Like
8

@Pr0tonX, thank you, this is the best advice I got as of now.