⚙️ PHP settype() Function

settype() in PHP is a built-in function used to explicitly convert or modify the data type of an existing variable. Unlike standard type casting which creates a temporary converted copy, settype() directly mutates the original variable's data type.

1️⃣ Converting a String to an Integer
When you pass a numeric string into settype() with the "integer" parameter, the original variable is converted into a true integer type.

$score = "100";

echo gettype($score); // Outputs: string

settype($score, "integer");

echo gettype($score); // Outputs: integer
var_dump($score);     // Outputs: int(100)

2️⃣ Converting Numbers to Floating-Point (double)
You can convert an integer or string representation into a float by using "float" or "double".

$price = 45;

settype($price, "float");

echo gettype($price); // Outputs: double
var_dump($price);     // Outputs: float(45)

3️⃣ Converting Values to Boolean
Non-empty values resolve to true, while 0, empty strings "", or null resolve to false.

$status = "1";
settype($status, "boolean");

var_dump($status); // Outputs: bool(true)

$emptyVal = 0;
settype($emptyVal, "boolean");

var_dump($emptyVal); // Outputs: bool(false)

4️⃣ Converting Scalar Values to Arrays
Converting a scalar value like a string or number into an array places that value into the first index ([0]).

$siteName = "TeachWebCode";

settype($siteName, "array");

print_r($siteName); 
/* Outputs:
Array
(
    [0] => TeachWebCode
)
*/

The target type string supplied to settype() must be one of the following valid PHP type aliases:

• "boolean" or "bool" → Casts to boolean.
• "integer" or "int" → Casts to integer.
• "float" or "double" → Casts to floating-point number.
• "string" → Casts to string.
• "array" → Casts to array structure.
• "object" → Casts to stdClass object.
• "null" → Sets variable value to NULL.