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Added "The Basics" section
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Nick Adams
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_posts/05-05-01-The-Basics.md
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_posts/05-05-01-The-Basics.md
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---
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isChild: true
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---
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## The Basics
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PHP is a vast language that allows coders of all levels the ability to produce code not only quickly, but efficiently.
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However while advancing through the language, we often forget the basics that we first learnt (or overlooked) in favor
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of short cuts and/or bad habits. To help combat this common issue, this section is aimed at reminding coders of the
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basic coding practices within PHP.
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* Continue reading on [The Basics](/pages/The-Basics.html)
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pages/The-Basics.md
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pages/The-Basics.md
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---
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layout: page
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title: The Basics
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---
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# The Basics
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## Comparison operators
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Comparison operators are an often overlooked aspect of PHP, which can lead to many unexpected outcomes. One such
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problem stems from strict comparisons (the comparison of booleans as integers).
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{% highlight php %}
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<?php
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$a = 5; // 5 as an integer
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var_dump($a == 5); // compares value; return true
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var_dump($a == '5'); // compares value (ignore type); return true
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var_dump($a === 5); // compares type/value (integer vs. integer); return true
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var_dump($a === '5'); // compares type/value (integer vs. string); return false
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/**
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* Strict comparisons
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*/
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if (strpos('testing', 'test')) { // 'test' is found at position 0, which is interpreted as the boolean 'false'
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// code...
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}
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vs.
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if (strpos('testing', 'test') !== false) { // true, as strict comparison was made (0 !== false)
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// code...
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}
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{% endhighlight %}
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* [Comparison operators](http://php.net/manual/en/language.operators.comparison.php)
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* [Comparison table](http://php.net/manual/en/types.comparisons.php)
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## Conditional arguments
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### If statements
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While using 'if/else' statements within a function or class, there is a common misconception that 'else' must be used
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in conjunction to declare potential outcomes. However if the outcome is to define the return value, 'else' is not
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necessary as 'return' will end the function, causing 'else' to become moot.
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{% highlight php %}
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<?php
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function test($a)
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{
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if ($a) {
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return true;
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} else {
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return false;
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}
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}
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vs.
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function test($a)
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{
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if ($a) {
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return true;
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}
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return false; // else is not necessary
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}
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{% endhighlight %}
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* [If statements](http://php.net/manual/en/control-structures.if.php)
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### Switch statements
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Switch statements are a great way to avoid typing endless if's and elseif's, but there are a few things to be aware of:
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- Switch statements only compare values, and not the type (equivalent to '==')
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- They Iterate case by case until a match is found. If no match is found, then the default is used (if defined)
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- Without a 'break', they will continue to implement each case until reaching a break/return
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- Within a function, using 'return' alleviates the need for 'break' as it ends the function
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{% highlight php %}
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<?php
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$answer = test(2); // the code from both 'case 2' and 'case 3' will be implemented
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function test($a)
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{
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switch ($a) {
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case 1:
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// code...
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break; // break is used to end the switch statement
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case 2:
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// code... // with no break, comparison will continue to 'case 3'
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case 3:
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// code...
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return $result; // within a function, 'return' will end the function
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default:
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// code...
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return $error;
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}
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}
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{% endhighlight %}
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* [Switch statements](http://php.net/manual/en/control-structures.switch.php)
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* [PHP switch](http://phpswitch.com/)
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## Global namespace
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While using namespaces, you may find your code being executed in the wrong scope for internal methods. To fix this,
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define the method globally by using a backslash before the method.
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{% highlight php %}
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<?php
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namespace phptherightway;
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function fopen()
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{
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$file = \fopen(); // our function name is the same as an internal function.
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// execute globally by adding "\".
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}
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function array()
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{
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$iterator = new \ArrayIterator(); // ArrayIterator is an internal class. Using it without a backslash
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// will execute it within the namespace scope.
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}
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{% endhighlight %}
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* [Global space](http://php.net/manual/en/language.namespaces.global.php)
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* [Global rules](http://php.net/manual/en/userlandnaming.rules.php)
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## Strings
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### Concatenation
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- If your line extends beyond the recommended line length (120 characters), consider concatenating your line
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- For readability it's best to use concatenation operators over concatenating assignment operators
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- While within the original scope of the variable, indent when concatenation uses a new line
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{% highlight php %}
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<?php
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$a = 'Multi-line example'; // concatenating assignment operator (.=)
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$a .= "\n";
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$a .= 'of what not to do';
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vs.
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$a = 'Multi-line example' // concatenation operator (.)
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. "\n" // indenting new lines
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. 'of what to do';
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{% endhighlight %}
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* [String Operators](http://php.net/manual/en/language.operators.string.php)
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### String types
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String types are a constant feature within the PHP community, but hopefully this section will explain the
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differences between the string types and their benefits/uses.
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#### Single quotes
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Single quotes are the simplest way to define a string and are often the quickest. Their quickness stems from PHP not
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parsing the string (doesn't parse for variables). They're best suited for:
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- Strings that do not need to be parsed
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- Writing of a variable into plain text
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{% highlight php %}
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<?php
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echo 'This is my string, look at how pretty it is.'; // no need to parse a simple string
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/**
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* Output:
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*
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* This is my string, look at how pretty it is.
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*/
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{% endhighlight %}
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* [Single quote](http://www.php.net/manual/en/language.types.string.php#language.types.string.syntax.single)
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#### Double quotes
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Double quotes are the Swiss army knife of strings, but are slower due to the string being parsed. They're best
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suited for:
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- Escaped strings
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- Strings with multiple variables and plain text
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- Condensing multi-line concatenation, and improving readability
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{% highlight php %}
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<?php
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echo 'phptherightway\'s is ' . $adjective . '.' // a single quotes example that uses multiple concatenating for
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. "\n" // variables and escaped string
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. 'I love learning' . $code . '!';
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vs.
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echo "phptherightway's is $adjective.\n I love learning $code!" // Instead of multiple concatenating, double quotes
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// enables us to use a parsable string
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{% endhighlight %}
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While using double quotes that contain variables, it's often the case that the variable will be touching another
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character. This will result in PHP not parsing the variable due to the variable being camouflaged. To fix this problem,
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wrap the variable within a pair of curly brackets.
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{% highlight php %}
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<?php
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$juice = 'plum';
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echo "I drank some juice made of $juices"; // $juice cannot be parsed
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vs.
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$juice = 'plum';
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echo "I drank some juice made of {$juice}s"; // $juice will be parsed
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/**
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* Complex variables will also be parsed within curly brackets
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*/
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$juice = array('apple', 'orange', 'juice');
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echo "I drank some juice made of {$juice[1]}s"; // $juice[1] will be parsed
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{% endhighlight %}
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* [Double quotes](http://www.php.net/manual/en/language.types.string.php#language.types.string.syntax.double)
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#### Nowdoc syntax
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Nowdoc syntax was introduced in 5.3 and internally behaves the same way as single quotes except it's suited toward the
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use of multi-line strings without the need for concatenating.
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{% highlight php %}
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<?php
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$str = <<<'EOD' // initialized by <<<
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Example of string
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spanning multiple lines
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using nowdoc syntax.
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$a does not parse.
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EOD; // closing 'EOD' must be on it's own line, and to the left most point
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/**
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* Output:
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*
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* Example of string
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* spanning multiple lines
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* using nowdoc syntax.
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* $a does not parse.
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*/
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{% endhighlight %}
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* [Nowdoc syntax](http://www.php.net/manual/en/language.types.string.php#language.types.string.syntax.nowdoc)
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#### Heredoc syntax
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Heredoc syntax internally behaves the same way as double quotes except it's suited toward the use of multi-line
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strings without the need for concatenating.
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{% highlight php %}
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<?php
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$a = 'Variables';
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$str = <<<'EOD' // initialized by <<<
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Example of string
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spanning multiple lines
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using nowdoc syntax.
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$a are parsed.
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EOD; // closing 'EOD' must be on it's own line, and to the left most point
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/**
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* Output:
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*
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* Example of string
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* spanning multiple lines
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* using nowdoc syntax.
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* Variables are parsed.
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*/
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{% endhighlight %}
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*[Heredoc syntax](http://www.php.net/manual/en/language.types.string.php#language.types.string.syntax.heredoc)
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## Ternary operators
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Ternary operators are a great way to condense code, but are often used in excess. While ternary operators can be
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stacked/nested, it is advised to use one per line for readability.
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{% highlight php %}
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<?php
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$a = 5;
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echo ($a == 5) ? 'yay' : 'nay';
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vs.
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// nested ternary
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$b = 10;
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echo ($a) ? ($a == 5) ? 'yay' : 'nay' : ($b == 10) ? 'excessive' : ':('; // excess nesting, sacrificing readability
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{% endhighlight %}
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Ternary operators also have their limitations and cannot be used to 'return' a value.
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{% highlight php %}
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<?php
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$a = 5;
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echo ($a == 5) ? return true : return false; // this example will output an error
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{% endhighlight %}
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* [Ternary operators](http://php.net/manual/en/language.operators.comparison.php)
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## Variable declarations
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At times, coders attempt to make their code "cleaner" by declaring predefined variables with a different name. What
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this does in reality is to double the memory consumption of said script. For the example below, let's say
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$_GET\['about_me'\] contains 1MB worth of data, by copying the variable you've increased the scripts execution to 2MB.
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{% highlight php %}
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<?php
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$about = $_GET['about_me']; // uses 2MB memory
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echo $about;
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vs.
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echo $_GET['about_me']; // uses 1MB memory
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{% endhighlight %}
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* [Performace tips](https://developers.google.com/speed/articles/optimizing-php)
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