Basic Syntax¶

In this section, we'll delve into the fundamental aspects of Zephir's syntax, covering topics such as file and namespace organization, variable declarations, syntax conventions, and other essential concepts.

Organizing Code in Files and Namespaces¶

Zephir introduces a structured approach to code organization. Each file should contain only one class, and every class must be within a namespace. The directory structure aligns with class and namespace names, similar to PSR-4 autoloading conventions.

For example:

mylibrary/
    router/
        exception.zep # MyLibrary\Router\Exception
    router.zep # MyLibrary\Router

Class in mylibrary/router.zep:

namespace MyLibrary;

class Router
{

}

Class in mylibrary/router/exception.zep:

namespace MyLibrary\Router;

class Exception extends \Exception
{

}

The file system structure must mirror the namespaces, ensuring consistency.

Instruction separation¶

In Zephir, semicolons can be used to separate statements and expressions, akin to Java, C/C++, and PHP:

myObject->myMethod(1, 2, 3); echo "world";

Comments¶

Zephir supports 'C'/'C++' style comments - single-line with // ... and multi-line with /* ... */:

// this is a one line comment

/**
 * multi-line comment
 */

Multi-line comments also serve as docblocks, influencing the generated code and providing documentation.

Variable Declarations¶

In Zephir, all variables used in a given scope must be declared. This gives important information to the compiler to perform optimizations and validations. Variables must be unique identifiers, and they cannot be reserved words.

// Declaring variables for the same type    in the same instruction
var a, b, c;

// Declaring each variable in separate lines
var a;
var b;
var c;

Variables can have optional initial default values:

// Declaring variables with default values
var a = "hello", b = 0, c = 1.0;
int d = 50; bool some = true;

Variable names are case-sensitive, the following variables are different:

// Different variables
var somevalue, someValue, SomeValue;

Variable Scope¶

Variables declared are locally scoped to the method where they are defined:

namespace Test;

class MyClass
{
    public function someMethod1()
    {
        int a = 1, b = 2;
        return a + b;
    }

    public function someMethod2()
    {
        int a = 3, b = 4;
        return a + b;
    }
}

Super Globals¶

Global variables are not supported in Zephir. However, access to PHP's super-globals is possible:

// Getting a value from _POST
let price = _POST["price"];

// Read a value from _SERVER
let requestMethod = _SERVER["REQUEST_METHOD"];

Local Symbol Table¶

Zephir does not implement the dynamic variable behavior found in PHP. The language does not have a local symbol table, as all variables are compiled into low-level variables without context awareness. To create a variable in the PHP symbol table, a specific syntax is used:

// Set variable $name in PHP
let {"name"} = "hello";

// Set variable $price in PHP
let name = "price";
let {name} = 10.2;