PHP Basics (ii)

Global namespace//do not see the following Chinese-English combination look

When using the namespaces, you could find that internal functions (internal (built-in) function) is hidden by functions you wrote. To fix this, refer to the global function by using a backslash before the function name.

<?phpnamespace phptherightway;function fopen () {    $file = \fopen ();    Our function name is the same as an internal function.                         Execute the function from the global space by adding '.} function Array () {    $iterator = new \arrayiterator ();    Arrayiterator is an internal class. Using its name without a backslash                                         //would attempt to resolve it within your namespace.}

Global space:

If no namespace is defined, all classes and functions are defined in the global space, as before the introduction of the namespace concept in PHP. Precede the name with a prefix \ means that the name is the name in the global space, even if the name is in a different namespace.

<?phpnamespace a\b\c;/* This function is A\b\c\fopen */function fopen () {      /* ... */     $f = \fopen (...);//Call global fopen function     return $f;} ?>

　

Stringsconcatenation

• If your line extends beyond the recommended line length (+ 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

<?php$a  = ' multi-line example ';    concatenating assignment operator (. =) $a. = "\ n"; $a. = ' of what ' does '; vs. $a = ' Multi-line example '      //Concaten ation operator (.)    . "\ n"                     //indenting new lines    . ' of what and do ';

　

String types

String types is a constant feature within the PHP community, but hopefully this section would explain the differences betw Een the string types and their benefits/uses.

Single quotes

Single quotes is the simplest-define a string and is often the quickest. Their speed stems from PHP not parsing the string (doesn ' t parse for variables). They ' re best suited for:

• Strings that does not need to be parsed
• Writing of a variable into plain text

<?phpecho ' This was my string, look at how pretty it was. ';    No need to parse a simple string/** * Output: * * This is my string and look at how pretty it is. */

　　

Double Quotes

Double quotes is the Swiss Army knife of strings, but is 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

<?phpecho ' Phptherightway is '. $adjective. '. '     A single quotes example this uses multiple concatenating for    . "\ n"                                       //variables and escaped string    . ' I love learning '. $code. ‘!‘; Vs.echo "Phptherightway is $adjective. \ n I Love learning $code!"  Instead of multiple concatenating, double quotes                                                               //enables us to use a parsable string

While using a double quotes that contain variables, it's often the case that the variable would be touching another character . This would 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.

<?php$juice = ' plum '; echo "I drank some juice made of $juices";    $juice cannot be parsedvs. $juice = ' plum '; echo "I drank some juice made of {$juice}s";    $juice'll be parsed/** * Complex variables would also be parsed within curly brackets * * $juice = array (' Apple ', ' orang E ', ' plum '); echo "I drank some juice made of {$juice [1]}s];   $juice [1] would be parsed

　　

Nowdoc syntax Heredoc syntax

See PHP Manual.

Ternary operators (ternary operator)

Ternary operators is a great the condense code, but is often used in excess. While ternary operators can be stacked/nested, it's advised to use one per line for readability.

<?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

　　

To ' return ' a value with ternary operators use the correct syntax.

<?php$a = 5;echo ($a = = 5)? return True:return false;    This example would output an errorvs. $a = 5;return ($a = = 5)? ' Yay ': ' Nope ';    This example would return ' Yay '

　　

Variable declarations

<?php$about = ' A very long string of text ';    Uses 2MB memoryecho $about; Vs.echo ' A very long string of text ';        Uses 1MB memory

　　

　

PHP Basics (ii)