PHP Programming: Features, Data Types, Functions, and More

Posted on Sep 26, 2024 in Computers

1. PHP Features

PHP is a popular language due to its simplicity and open-source nature. Here are some key features:

Performance

PHP scripts execute faster than those written in languages like JSP and ASP. PHP uses its own memory, reducing server workload and loading time, resulting in faster processing and better performance.

Other Features

  • Open Source
  • Familiar Syntax
  • Embedded
  • Platform Independent
  • Database Support
  • Error Reporting
  • Loosely Typed Language
  • Web Server Support
  • Security and Control

2. Difference Between echo and print

echo

  • Statement used to display output.
  • Can be used with or without parentheses.
  • Does not return any value.
  • Can pass multiple strings separated by commas.
  • Faster than print.

print

  • Statement used as an alternative to echo.
  • Can be used with or without parentheses.
  • Always returns an integer value of 1.
  • Cannot pass multiple arguments.
  • Slower than echo.

3. PHP Data Types

PHP supports 8 primitive data types:

Scalar Types

  • boolean
  • integer
  • float
  • string

Compound Types

  • array
  • object

Special Types

  • resource
  • NULL

4. PHP Operators

PHP operators perform operations on variables or values.

Operator Categories

  • Arithmetic Operators: +, -, *, /, %, **
  • Assignment Operators: =, +=, -=, *=, /=, %=
  • Bitwise Operators: &, |, ^, ~, <<, >>
  • Comparison Operators: ==, ===, !==, !=, <>, <, >, <=, >=, <=>
  • Incrementing/Decrementing Operators: ++, --
  • Logical Operators: and, or, xor, !, &&, ||
  • String Operators: .=
  • Array Operators: +, ==, !=, ===, !==, <>

Operand-Based Categories

  • Unary Operators: ++, --
  • Binary Operators: +, -, *, /
  • Ternary Operators: ?:

5. PHP Control Statements

if, else, elseif

  • if: Executes code if the condition is true.
  • if-else: Executes one block if true, another if false.
  • if-elseif-else: Combines multiple conditions.
  • Nested if: if block inside another if block.

switch

Executes one statement from multiple conditions.

6. PHP Array Types

  • Indexed Array: $fruits = ["Apple", "Banana", "Orange"];
  • Associative Array: $person = ["name" => "Suri", "Age" => 30, "Occupation" => "Developer", "City" => "Bengaluru"];
  • Multidimensional Array: Arrays within arrays.

7. Type Casting

Type Casting Operators

  • (int) or (integer)
  • (bool) or (boolean)
  • (float), (double), or (real)
  • (string)
  • (array)
  • (object)

Type Casting Functions

  • intval()
  • floatval()
  • strval()
  • settype()
  • gettype()

8. PHP Functions

Types of Functions

  • Built-in Functions: Predefined functions like var_dump(), fopen(), etc.
  • User-Defined Functions: Custom functions.
  • Anonymous Functions (Closures): Functions without a name.
  • Recursive Functions: Functions that call themselves.

9. Strings in PHP

PHP strings store and manipulate text.

String Specification

  • Single quoted
  • Double quoted
  • Concatenation
  • Escape sequences
  • Heredoc syntax
  • Nowdoc syntax

10. Connecting to MySQL

Uses MySQLi (MySQL Improved).

  1. Set up connection parameters.
  2. Create a connection using mysqli().
  3. Check the connection.
  4. Perform operations.
  5. Close the connection.