How can you access form field names like "r_DisplayName" or "$this->formFieldName" in PHP for string manipulation?

To access form field names like "r_DisplayName" or "$this->formFieldName" in PHP for string manipulation, you can use PHP's variable variables feature. This feature allows you to dynamically access variables based on the value of another variable. By using this feature, you can construct the variable name using the form field name and then manipulate the value accordingly.

// Example of accessing and manipulating form field names in PHP
$r_DisplayName = "JohnDoe";
$formFieldName = "r_DisplayName";

// Using variable variables to access and manipulate form field names
$value = $$formFieldName; // Dynamically access variable based on form field name
echo "Original value: " . $value . "<br>";

// Manipulate the value
$newValue = strtoupper($value);
echo "Manipulated value: " . $newValue;