James Anderson

I'm fairly new to using Max, and am very new to using Javascript with Max. My eventual goal is to  treat lists as arrays in JS so that they can be modified and outputted as new lists. Unfortunately, I'm struggling with the basics! 

This code doesn't work in Max when sending the message '1 2 3 4':

Logged: 'js: no function list [script name]'

I'm sure it must be very simple but I can't work it out. Thanks in advance!

Hi everyone

I'm fairly new to using Max, and am very new to using Javascript with Max. My eventual goal is to  treat lists as arrays in JS...

max-not-printing-javascript-arrays

Try the max JS function arrayfromargs() around your “listin” variable.

In Max, when handling incoming messages, you need to convert the 

 object into an array before performing operations on it. Like this

(arguments); // Convert arguments to an array

((x) => x * 2); // Perform the desired operation

Welcome to the world of Max and JavaScript! It’s great that you’re exploring this combination. Let’s tackle the issue you’re facing.

Your goal is to treat lists as arrays in JavaScript within Max, allowing you to modify them and output new lists. Your initial code works as expected in a pure JavaScript environment, but it doesn’t behave the same way in Max. Specifically, the following code doesn’t produce the desired output:

function list() {
    var array1 = arguments.map((x) => x * 2);
    post(array1);
}


When you send the message ‘1 2 3 4’, you encounter the error message: ‘js: no function list [script name]’.

 object behaves differently from standard JavaScript. Instead, you can use the 

 object to receive data. Let’s modify your code accordingly:

function list() {
    var array1 = arrayfromargs(arguments).map((x) => x * 2);
    post(array1);
}


Now, when you send the message ‘1 2 3 4’, you should see the expected output: ‘js: [2, 4, 6, 8]’.

Remember that Max and JavaScript have some unique interactions, so adapting your code to the Max environment is essential. 

Thanks for the tip, Tyler. With arrayfromargs() I'm able to print the array without any modifications, but it still doesn't work when I attempt to put a calculation in the mix. Neither of these sets of code have worked:

var array1 = arrayfromargs(arguments).map((x) => x * 2);

var array1 = arrayfromargs(listIn).map((x) => x * 2);

Ah, .map() may not be in available JS ES5, which is the version Max uses.

.map() is available in ES5, but the problem turned out to be something else that isn't: arrow functions. So thanks for the clue! 

For anybody reading in the future, I got the code working with a different function syntax:

var array1 = arrayfromargs(arguments).map(function(x) {

Max not printing Javascript arrays