PHP 8 introduced union types as a new feature in the language. Union types allow you to specify that a parameter or return value of a function or method can accept multiple different types. This provides more flexibility in your code and helps you write more expressive and precise type hints.
- Union types can make your code more robust and self-documenting because they explicitly state what types are allowed for a particular parameter or return value.
- It also reduces the need for additional type checking in your code, as PHP will enforce type compatibility at the function level.
In PHP 8, you can define union types using the vertical bar (|) to separate the different types you want to allow. For example:
function foo(int|string $value): void {
// $value can be an integer or a string
// You can use it as such within the function
}
In the example above, the foo function accepts a parameter $value that can be either an int or a string. This means you can pass an integer or a string as an argument to the function, and it will work correctly.
Here’s a simple example of union types in PHP 8:
function displayValue(int|string $value) {
echo "The value is: $value";
}
displayValue(42); // Passing an integer
displayValue("Hello"); // Passing a string
In this example, the displayValue function accepts a parameter $value with a union type of int|string. This means it can accept both integers and strings as arguments. When you call the function with an integer or a string, it will work correctly and display the value.
