Namespaces is a method with which we can group variable,function or objects so that we can have more than one variable or function or object with same name .

Namespaces were introduced into PHP from version 5.3 onwards

Use

• Helps to prevent accidentally re-defining functions, classes, constants, …
• Avoids having to use long, highly descriptive class names
• Constants, classes, traits, interfaces and functions are affeced by the use of namespaces
• Create sub-namespaces to sub-divide a library

Declaring Namespaces

• Must declare the use of namespaces with the keyword “namespace” at the beginning of the code file (right after <?PHP)
• Use one namespace per code file (best practice)
• Unless a namespace is defined, constants, classes, functions, traits and interfaces are defined with the global namespace
• Within a namespace qualifying with a “\” references the global namespace
• Once code elements within a single namespace are defined, they can be used in other php files

Example

<?php
 namespace php;
 class php
 {
 public function phpcodez()
 {
 echo 'Function1 <br />';
 }
 }
 namespace codez;
 class codez
 {
 public function phpcodez()
 {
 echo 'Function2 <br />';
 }
 }

$phpcodez = new phpphp();
 $phpcodez->phpcodez();

$phpcodez = new codezcodez();
 $phpcodez->phpcodez();

?>