An exciting feature was introduced in PHP7 - optional strict mode. By enabling strict mode, developers can better create and maintain high-quality code. This article will introduce how to use strict mode in PHP7 and provide some specific code examples.
First, let us understand what strict mode is. Strict mode is a programming option in PHP7 that enforces stricter error checking rules and standards to improve the quality and maintainability of your code. In default mode, PHP automatically performs type conversions when an error is encountered, which can cause some potential problems. The goal of strict mode is to help developers avoid these potential problems and deliver more reliable and robust code.
To enable strict mode in PHP7, we need to add the following code at the top of the script:
declare(strict_types=1);
This statement tells the PHP interpreter to enable strict mode in the current script. Next, we'll see some concrete code examples to demonstrate the benefits of strict mode.
First, let's consider a simple function that takes two parameters and returns their sum:
function addNumbers($a, $b) { return $a + $b; }
In default mode, PHP automatically does type conversion, so we can pass Give this function any type of argument and it will work fine. But in strict mode, we need to explicitly declare the type of the parameter:
function addNumbers(int $a, int $b): int { return $a + $b; }
Now, if we try to pass a non-integer type parameter to this function, PHP will throw a type error at runtime. This reminds developers that parameters should be integers, avoiding potential type-related issues.
Another benefit of strict mode is that it enforces checks on function return types. In default mode, we can not specify the return type of the function, or return a type that does not match the function declaration. But in strict mode, we must specify the return type of the function and ensure that the returned value type is correct:
function divideNumbers(int $a, int $b): float { return $a / $b; }
In this example, we declare that the function returns a float type. If we try to return a value of type integer, PHP will throw a type error, ensuring that our function always returns the correct type.
Strict mode also treats arrays and null values differently. In default mode we can assign any value to the array, even null values. But in strict mode, we must explicitly declare the type of the array and whether the array is allowed to be empty:
function processArray(array $arr): void { // do something with $arr } function processNullableArray(?array $arr): void { // do something with $arr }
In this example, the processArray function only accepts non-empty arrays as parameters, while the processNullableArray function accepts An empty array as parameter. This way we can operate safely inside the function without the need for additional type checking.
By using strict mode, we can better create and maintain high-quality code. It provides stricter rules in type checking and error handling, reducing potential bugs and errors. Although strict mode requires some extra work, it provides more robust code and better maintainability. In modern large-scale projects, it is a good practice to use strict mode.
To summarize, the optional strict mode introduced in PHP7 provides developers with a better way to create and maintain high-quality code. Strict mode helps us avoid potential problems and improve the reliability of our code by enforcing stricter type checking and error handling rules. Although it requires extra work, it gives us better code quality and maintainability. If you haven’t tried strict mode yet, I encourage you to use it on your next project and see the difference it can make in your code.
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