CODEWITHSUNDEEP
p5.js
GMath314
GMath314

Reputation: 73

mousePressed method is launching prematurely in p5js

I created the following function using p5.js and the mousePressed method is firing immediately when the page loads. It doesn't wait for me to click the button object to display a paragraph containing the ans variable.

What am I doing wrong?

function setup() {
    var ans = generate();
    var checkMe = createButton('Check Answer');
    checkMe.mousePressed(createP(ans));
}

Upvotes: 0

Views: 198

Answers (1)

Kevin Workman
Kevin Workman

Reputation: 42176

Let's take a closer look at this line:

checkMe.mousePressed(createP(ans));

This could be split into two lines:

var createPValue = createP(ans);
checkMe.mousePressed(createPValue);

In other words, you're calling the createP() function, and then passing the value returned (which is probably undefined) into the mousePressed() function. I'm surprised this doesn't cause an error in the JavaScript console.

Instead, what you want to do is pass a function as a value into the mousePressed() function. Since you need to use a parameter, you might do that this way:

function callCreateP(){
  createP(ans);
}
checkMe.mousePressed(callCreateP);

Notice that callCreateP doesn't have parentheses () after its name when we pass it into the mousePressed() function. That's because we're using it as a value instead of directly calling it.

You could shorten that to this line:

checkMe.mousePressed(function(){ createP(ans); });

Upvotes: 1

Related Questions