I’m having trouble getting Puppeteer to run JavaScript code that I usually execute in the browser’s Dev Tools console. My goal is to print out all the items in an array.
I’ve looked at the Puppeteer docs and tried different approaches using page.evaluate(), but nothing seems to work. Here’s a simplified example of what I’m trying to do:
const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.goto('https://example.com');
const result = await page.evaluate(() => {
const myArray = ['apple', 'banana', 'cherry'];
return myArray.map(item => item);
});
console.log(result);
await browser.close();
This code doesn’t produce any errors, but it also doesn’t give me the expected output. Can someone point out what I’m doing wrong or suggest a better way to achieve this? Thanks for any help!
I’ve encountered similar issues when working with Puppeteer. The code you’ve provided looks generally correct, but there might be a few things to consider.
First, make sure you’re actually logging the result. In your example, you’re returning the array from page.evaluate(), but not doing anything with it afterwards. Try console.logging the result outside of the evaluate function.
Also, if you’re trying to access variables or functions that exist in your Node.js environment inside page.evaluate(), remember that it runs in the context of the browser. You might need to pass those as arguments.
One approach I’ve found useful is to break down complex operations into smaller evaluate() calls. This can help isolate where things might be going wrong.
Lastly, don’t forget to handle potential errors. Wrapping your Puppeteer code in a try-catch block can save you a lot of headaches when debugging.
Hope this helps you troubleshoot your issue!
Your approach is on the right track, but there’s a simpler way to achieve what you want. Instead of using map(), which creates a new array, you can directly return myArray from the evaluate function. Here’s how you can modify your code:
const result = await page.evaluate(() => {
const myArray = ['apple', 'banana', 'cherry'];
return myArray;
});
console.log(result);
This should print out the entire array. If you specifically want to print each item separately, you can do that after the evaluate function:
result.forEach(item => console.log(item));
Remember, page.evaluate() runs in the browser context, so any variables or functions you want to use inside it need to be defined within that scope or passed as arguments. If you’re still having issues, double-check that the page has fully loaded before running your script.
hey there! i’ve run into this before. make sure ur actually printing the result outside the evaluate function. also, try using console.log inside the evaluate to see if its working:
const result = await page.evaluate(() => {
const myArray = ['apple', 'banana', 'cherry'];
console.log(myArray); // This will show in browser console
return myArray;
});
console.log(result); // This will show in Node.js console
hope that helps! lemme know if u need anything else