VARIABLE DECLARATION IN PHP - PHP LESSON 4 STUDENTSBLOG100

Variables:
Variables are used to hold different types of data. Some data types are Integer, character, float, double, string etc..

PHP Variable Declaration :

• Variable have to begin with a dollar sign ($).
• After the $ symbol, variable names can be begin with a letter or a Under score(_). Variable names cannot be started with a number in php.
• Variable names are case sensitive. That is $firstname is a completely different variable than $FirstName.

PHP Data Types :

Segment	Type	Description
Scalar types	Boolean	Logical TRUE or FALSE
	Integer	Whole numbers: e.g 1,2,3...
	Float (double)	Numbers with decimal notations e.g., 12.56 or 345.456
	String	Characters, letters, or numbers (usually defined within double quotes): e.g., “Hello there” or “123AsR”
Compound types	Array	A collection of keys with their values, arrays can hold other arrays (multidimensional);
	Object	The basics for class definitions and object-oriented programming;
Special types	Null	Defines a variable with no value; the variable exists, but contains nothing (not an empty string, not the value 0, nothing)
	Resource	Stores a reference to functions, databases, files, or other resources outside of PHP

Assigning Values to Variables:
There are two ways to assign values to variables,they are

• by value
• by reference

By Value:

Syntax:

• $variablename = value;

Example:

• $a = 12;
• $b = "StudentsBlog100";

By reference:

Syntax:

• $firstname = "Peter"; // assigned by value
• $fname = &$firstname; // $firstname is assigned to $fname by reference.

---

Example:
 
<?php $a="Hello world!"; //String $b=5; //Integer $c=10.5; //Float echo "$a <br>"; //Printing value of a. <br> is a html tag to print stmt's in next line.. echo $b; //Printing value of b. echo "<br>"; //<br> is a html tag to print stmt's in next line.. echo $c; //Printing value of c. ?> Output:

Hello StudentsBlog100! 

 5 

10.5

---

Lesson 3 ◄ Previous | Main Page | Next ► Lesson 5

---