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:
 
Output:
Hello StudentsBlog100! 
 5 
10.5

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