How to generate custom log file in magento 2?

Question

I have tried generating custom log file using helper and logger but the file did not generate.

Answer 1

Put below code in anywhere in magento2 :-

$writer = new \Zend\Log\Writer\Stream(BP . '/var/log/custom.log');
$logger = new \Zend\Log\Logger();
$logger->addWriter($writer);
$logger->info($yourData);

Answer 2

Logger format depends on the magento version. so i have given different formats as per magento version support. please check and try on it.

Magento use below code for 2.4.3 and above versions.

$writer = new \Zend_Log_Writer_Stream(BP . '/var/log/custom.log');
$logger = new \Zend_Log();
$logger->addWriter($writer);
$logger->info('Test the log');
$logger->info(print_r($object->getData(), true));

Magento use below code for Magento 2.4.2 and below versions.

$writer = new \Zend\Log\Writer\Stream(BP . '/var/log/custom.log');
$logger = new \Zend\Log\Logger();
$logger->addWriter($writer);
$logger->info('Custom message'); 
$logger->info(print_r($object->getData(), true));