Merge pull request codeguy#166 from telephone/basics

Added "The Basics" section

_posts/05-05-01-The-Basics.md

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+---
+isChild: true
+---
+
+## The Basics
+
+PHP is a vast language that allows coders of all levels the ability to produce code not only quickly, but efficiently. 
+However while advancing through the language, we often forget the basics that we first learnt (or overlooked) in favor 
+of short cuts and/or bad habits. To help combat this common issue, this section is aimed at reminding coders of the 
+basic coding practices within PHP.
+
+* Continue reading on [The Basics](/pages/The-Basics.html)

pages/The-Basics.md

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