Strict type checking means it strictly checks the data types.
If you give the declare(strict_type=1) at the start of the program.
Because of this, the program checks the type of every value everywhere.
When you define the function with a data type and its parameters, and when you call the function then it should match otherwise it displays the type error message.
Uses:
- It prevents data type errors in the program.
- It ensures accuracy by enforcing strict data types throughout the program.
Syntax:
<?php
declare(strict_types=1); // It enforces the strict type checking.
function addNumbers(int $a, int $b) {
return $a + $b;
}
?>
Example:
<?php
declare(strict_types=1); // It enforces the strict type checking.
function multiplyNumbers(int $x, int $y) {
return $x * $y;
}
// Correct usage
echo multiplyNumbers(5, 3); // Works fine, output: 15
// Incorrect usage
echo multiplyNumbers(5, "3"); // TypeError: Argument 2 must be of type int
?>
Output:
15 Incorrect usage: Fatal error: Uncaught TypeError: multiplyNumbers(): Argument #2 ($y) must be of type int, string given