PHP

define constant in php

<?php
	define("emp_name","Kumar D");
	echo constant("emp_name");
	//or 
	echo emp_name;
?>

php constant

<?php
define("PI",3.14);
echo PI;
echo constant("PI");
?>

PHP constants

//define(name,value);

define("PI",3.1419); 

php constant name with variable

echo constant($constant_name);

class constants in php

<?php
class MyClass
{
    const CONSTANT = 'constant value';

    function showConstant() {
        echo  self::CONSTANT . "
";
    }
}

echo MyClass::CONSTANT . "
";

$classname = "MyClass";
echo $classname::CONSTANT . "
";

$class = new MyClass();
$class->showConstant();

echo $class::CONSTANT."
";
?>

PHP constant

class Human {
  const TYPE_MALE = 'm';
  const TYPE_FEMALE = 'f';
  const TYPE_UNKNOWN = 'u'; // When user didn't select his gender
  
  .............
}

how to create constant in php

<?php
  
#Syntax to define a constant is Define("Name","Value","Case-insensitive")

#For case-insensitive, sensitive is default
  
define("Tau","6.28318530718","true");
echo tAU;

#Fun fact: Tau = Pi x 2
?>

Constants In PHP

<?php
define("A", 100);
define("B", 200);
echo A;
echo "<br>";
echo B;
?>

PHP Constants

<?php
define("GREETING", "Welcome to my profile");
echo GREETING;
?>

php variable constant

if (...) {
     const FOO = 'BAR';    // Invalid
 }
 // but
 if (...) {
     define('FOO', 'BAR'); // Valid
 }