Superglobals

Since: 0.2

Accessing a super-global variable directly is considered a bad practice. These variables should be encapsulated in objects that are provided by a framework, for instance.

Example

class Foo {
    public function bar() {
        $name = $_POST['foo'];
    }
}

Source

Superglobals

Since: 0.2

Accessing a super-global variable directly is considered a bad practice. These variables should be encapsulated in objects that are provided by a framework, for instance.

Example

class Foo {
    public function bar() {
        $name = $_POST['foo'];
    }
}

Source

Superglobals

Since: 0.2

Accessing a super-global variable directly is considered a bad practice. These variables should be encapsulated in objects that are provided by a framework, for instance.

Example

class Foo {
    public function bar() {
        $name = $_POST['foo'];
    }
}

Source

Superglobals

Since: 0.2

Accessing a super-global variable directly is considered a bad practice. These variables should be encapsulated in objects that are provided by a framework, for instance.

Example

class Foo {
    public function bar() {
        $name = $_POST['foo'];
    }
}

Source

Superglobals

Since: 0.2

Accessing a super-global variable directly is considered a bad practice. These variables should be encapsulated in objects that are provided by a framework, for instance.

Example

class Foo {
    public function bar() {
        $name = $_POST['foo'];
    }
}

Source

Superglobals

Since: 0.2

Accessing a super-global variable directly is considered a bad practice. These variables should be encapsulated in objects that are provided by a framework, for instance.

Example

class Foo {
    public function bar() {
        $name = $_POST['foo'];
    }
}

Source

Superglobals

Since: 0.2

Accessing a super-global variable directly is considered a bad practice. These variables should be encapsulated in objects that are provided by a framework, for instance.

Example

class Foo {
    public function bar() {
        $name = $_POST['foo'];
    }
}

Source

Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

• Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
• Code is considered more complex for each "break in the linear flow of the code"
• Code is considered more complex when "flow breaking structures are nested"

Further reading

• Cognitive Complexity docs
• Cognitive Complexity: A new way of measuring understandability

Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

• Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
• Code is considered more complex for each "break in the linear flow of the code"
• Code is considered more complex when "flow breaking structures are nested"

Further reading

• Cognitive Complexity docs
• Cognitive Complexity: A new way of measuring understandability

NPathComplexity

Since: 0.1

The NPath complexity of a method is the number of acyclic execution paths through that method. A threshold of 200 is generally considered the point where measures should be taken to reduce complexity.

Example

class Foo {
    function bar() {
        // lots of complicated code
    }
}

Source https://phpmd.org/rules/codesize.html#npathcomplexity

CyclomaticComplexity

Since: 0.1

Complexity is determined by the number of decision points in a method plus one for the method entry. The decision points are 'if', 'while', 'for', and 'case labels'. Generally, 1-4 is low complexity, 5-7 indicates moderate complexity, 8-10 is high complexity, and 11+ is very high complexity.

Example

// Cyclomatic Complexity = 11
class Foo {
1   public function example() {
2       if ($a == $b) {
3           if ($a1 == $b1) {
                fiddle();
4           } elseif ($a2 == $b2) {
                fiddle();
            } else {
                fiddle();
            }
5       } elseif ($c == $d) {
6           while ($c == $d) {
                fiddle();
            }
7        } elseif ($e == $f) {
8           for ($n = 0; $n < $h; $n++) {
                fiddle();
            }
        } else {
            switch ($z) {
9               case 1:
                    fiddle();
                    break;
10              case 2:
                    fiddle();
                    break;
11              case 3:
                    fiddle();
                    break;
                default:
                    fiddle();
                    break;
            }
        }
    }
}

Source https://phpmd.org/rules/codesize.html#cyclomaticcomplexity

ErrorControlOperator

Error suppression should be avoided if possible as it doesn't just suppress the error, that you are trying to stop, but will also suppress errors that you didn't predict would ever occur. Consider changing error_reporting() level and/or setting up your own error handler.

Example

function foo($filePath) {
    $file = @fopen($filPath); // hides exceptions
    $key = @$array[$notExistingKey]; // assigns null to $key
}

Source http://phpmd.org/rules/cleancode.html#errorcontroloperator

StaticAccess

Since: 1.4.0

Static access causes unexchangeable dependencies to other classes and leads to hard to test code. Avoid using static access at all costs and instead inject dependencies through the constructor. The only case when static access is acceptable is when used for factory methods.

Example

class Foo
{
    public function bar()
    {
        Bar::baz();
    }
}

Source https://phpmd.org/rules/cleancode.html#staticaccess

ElseExpression

Since: 1.4.0

An if expression with an else branch is basically not necessary. You can rewrite the conditions in a way that the else clause is not necessary and the code becomes simpler to read. To achieve this, use early return statements, though you may need to split the code it several smaller methods. For very simple assignments you could also use the ternary operations.

Example

class Foo
{
    public function bar($flag)
    {
        if ($flag) {
            // one branch
        } else {
            // another branch
        }
    }
}

Source https://phpmd.org/rules/cleancode.html#elseexpression

ElseExpression

Since: 1.4.0

An if expression with an else branch is basically not necessary. You can rewrite the conditions in a way that the else clause is not necessary and the code becomes simpler to read. To achieve this, use early return statements, though you may need to split the code it several smaller methods. For very simple assignments you could also use the ternary operations.

Example

class Foo
{
    public function bar($flag)
    {
        if ($flag) {
            // one branch
        } else {
            // another branch
        }
    }
}

Source https://phpmd.org/rules/cleancode.html#elseexpression

StaticAccess

Since: 1.4.0

Static access causes unexchangeable dependencies to other classes and leads to hard to test code. Avoid using static access at all costs and instead inject dependencies through the constructor. The only case when static access is acceptable is when used for factory methods.

Example

class Foo
{
    public function bar()
    {
        Bar::baz();
    }
}

Source https://phpmd.org/rules/cleancode.html#staticaccess

UnusedLocalVariable

Since: 0.2

Detects when a local variable is declared and/or assigned, but not used.

Example

class Foo {
    public function doSomething()
    {
        $i = 5; // Unused
    }
}

Source https://phpmd.org/rules/unusedcode.html#unusedlocalvariable

UnusedLocalVariable

Since: 0.2

Detects when a local variable is declared and/or assigned, but not used.

Example

class Foo {
    public function doSomething()
    {
        $i = 5; // Unused
    }
}

Source https://phpmd.org/rules/unusedcode.html#unusedlocalvariable

UnusedLocalVariable

Since: 0.2

Detects when a local variable is declared and/or assigned, but not used.

Example

class Foo {
    public function doSomething()
    {
        $i = 5; // Unused
    }
}

Source https://phpmd.org/rules/unusedcode.html#unusedlocalvariable

CamelCaseVariableName

Since: 0.2

It is considered best practice to use the camelCase notation to name variables.

Example

class ClassName {
    public function doSomething() {
        $data_module = new DataModule();
    }
}

Source

CamelCaseMethodName

Since: 0.2

It is considered best practice to use the camelCase notation to name methods.

Example

class ClassName {
    public function get_name() {
    }
}

Source

CamelCaseMethodName

Since: 0.2

It is considered best practice to use the camelCase notation to name methods.

Example

class ClassName {
    public function get_name() {
    }
}

Source