What is the significance of the isset() function in PHP and how does it impact the conditional statements in the code snippet?

The isset() function in PHP is used to determine if a variable is set and is not NULL. This is significant in conditional statements as it allows you to check if a variable exists before using it, preventing errors and warnings. By using isset() in conditional statements, you can ensure that your code runs smoothly without encountering undefined variable errors.

// Check if the variable is set before using it in a conditional statement
if(isset($variable)){
    // Perform actions using the variable
    echo $variable;
} else {
    // Handle the case where the variable is not set
    echo "Variable is not set.";
}