How can one troubleshoot and debug PHP code that is not displaying correctly in a web browser?

To troubleshoot and debug PHP code that is not displaying correctly in a web browser, you can start by checking for syntax errors, missing semicolons, or typos in the code. You can also use functions like var_dump() or echo statements to output variables and values to help identify where the issue might be occurring. Additionally, using an integrated development environment (IDE) with debugging tools can help pinpoint errors more efficiently.

```php
<?php
// Example PHP code with a syntax error
$variable = "Hello World"
echo $variable;
?>
```

In this example, the missing semicolon after the variable assignment will cause a syntax error. Adding the semicolon after "Hello World" will fix the issue and the code will display correctly in the web browser.