Introduction to new features in PHP7

In this article, we mainly share with you the new features in PHP7 that we should learn and use, hoping to help everyone.

PHP7 was officially released in November 2015. This update can be said to be an important milestone for PHP. It will bring significant performance improvements and new features, and improve some features of the previous version. The editor of this article will work with you to understand and discuss the new features in PHP7.

1. Scalar type declaration

We know that PHP is a weakly typed programming language, so it does not provide any method to specify the type of input parameters and return values. PHP7 breaks this status quo and adds support for scalar types (int , float, string, bool) declaration support, add the declare(strict_types=1) instruction to declare whether strict type checking, let’s look at a piece of code:

(strict_types=) { $x + $y;} add(, );

Valid types are: class/interface name, self, array, callable, bool, float, int and string.

?? ——NULL merge Operator

The NULL coalescing operator has been added to PHP7. Don’t underestimate this “??”. With it, we can easily obtain a parameter and provide a parameter when it is empty. default value. How does the ?? operator return the left side if the value on its left side exists and is not NULL, otherwise its right side value will be returned. Let’s experience the power of the ?? operator through the following piece of code.

<?php
 // 获取user参数的值(如果为空，则用&#39;nobody&#39;)
 // PHP5中我们这样来实现: $username = isset($_GET[&#39;user&#39;]) ? $_GET[&#39;user&#39;] : &#39;nobody&#39;;
 // PHP7中，使用??运算符更便捷: $username = $_GET[&#39;user&#39;] ?? &#39;nobody&#39;; 
?>

Anonymous class

As the name suggests, an anonymous class does not have a class name, and its declaration and instantiation are at the same time. PHP7 supports instantiating an anonymous class through new class, which can be used to replace some " Complete class definition of "Incineration".

echo ( {     {       ;    }})->myMethod();

More Errors can be handled with exceptions

More Errors in PHP7 become catchable Exceptions and are returned to the developer. If they are not caught, they are Errors. If they are caught, they become Errors. It is an Exception that can be handled within the program. By default, Error will directly cause the program to interrupt, while PHP7 captures and handles it through try/catch blocks, allowing the program to continue executing, providing programmers with more flexible options.

Code example:

nonExistFunction($arg);

At this time, the above code will prompt the error "Fatal error: Call to a member function method() on a non-object", and this fatal error will stop the following Code execution continues.

So if you want to continue executing the code, you can solve it through exception handling:

{    nonExistFunction($arg);  }  (EngineException $e ) {     ;}

Combined with the comparison operator (<=>)

Not much to explain , let’s look directly at the sample code. You can easily understand the function of this operator through the code.

{    ($a < $b) ?  : (($a > $b) ?  : )}  {    $a <=> $b;}

Define array constants

In the past, when we used define() to define constants, the data type only supported scalars, but in PHP7, it supports defining constants of array types.

define('MYCONSTANT', array('a','b','c'))

There are many new features in PHP7. Today we will introduce these first. We will continue to update them in the future. We also welcome additions from PHPers. Let’s communicate, learn and make progress together.

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