Why have jsPsych methods suddenly stopped working on my computer?

[sophief10]

Hello all!

While working on an experiment, I suddenly found that the jsPsych.randomization.shuffle() method would not work properly. I tried to execute the following code:

var numbers = [1, 2, 3, 4, 5];

var numbers_randomized = [];

var newArray = function() {
        numbers_randomized = jsPsych.randomization.shuffle(numbers);
        return numbers_randomized;
};

var test = {
        type: 'call-function',
        func: newArray
};
finalTimeline.push(test);

console.log(numbers_randomized);

When I execute the console.log function, I receive an empty array in return (i.e., the newArray function failed). I am unsure why that is happening. All of the necessary plugin scripts have been loaded into the experiment, so I suspect that the problem stems from a syntax error. However, the code looks fine to me (though I am an inexperienced coder).

Would someone please tell me why my code is not working?

For reference, I am using jsPsych version 6.3.1.

[becky-gilbert]

Hi @woodenchair, the issue here is that the call-function plugin doesn't run the func function until after the experiment starts, when jsPsych reaches the test trial in your experiment timeline. But your console.log is in your main script so it's running before the function is called (when the page loads, before the experiment starts).

You can move the console.log into the newArray function to see when the function is called and to check that the randomization is working:

var newArray = function() {
  numbers_randomized = jsPsych.randomization.shuffle(numbers);
  console.log(numbers_randomized);
  return numbers_randomized;
};

You can also try calling the newArray function before the console.log in your main script to immediately see the result:

var numbers = [1, 2, 3, 4, 5];

var numbers_randomized = [];

var newArray = function() {
  numbers_randomized = jsPsych.randomization.shuffle(numbers);
  return numbers_randomized;
};

newArray();
console.log(numbers_randomized)

[sophief10]

Thank you @becky-gilbert !