What are some common mistakes that PHP beginners make when trying to incorporate conditional statements, like if-else, into their code?

One common mistake beginners make when using conditional statements in PHP is forgetting to include the opening and closing curly braces for the code block inside the if or else statement. This can lead to unexpected behavior as only the next line of code is considered part of the conditional block. To solve this issue, always remember to enclose the code block within curly braces to ensure that all statements inside the block are executed conditionally.

// Incorrect way without curly braces
if ($condition)
    echo "This line is conditionally executed";
    echo "This line is always executed";

// Correct way with curly braces
if ($condition) {
    echo "This line is conditionally executed";
    echo "This line is also conditionally executed";
}