Strings

1. String Interpolation
2. If String Contains
3. String Replacement
4. Combining Strings (concatenation)
5. Grep in PHP
6. Input Validation

Arrays

1. Indexed Arrays
2. Associative Arrays
3. Split a String Into an Array
4. Reordering Array Elements
5. Removing Duplicated Array Values
6. Removing Elements From Arrays

Functions

1. Functions
2. Nested Functions
3. Named Parameters

Object Oriented PHP

1. Properties and Methods
2. Inheritance
3. Dependency injection
4. Namespaces
5. One Big Class vs Multiple
6. Factory Classes

Conditional Execution

1. If, Else if, Else
2. Shortened If, Else
3. Switch Statements

Looping and Recursion

1. While and For loops
2. Foreach and Array_walk
3. Foreach With Square Bracket Syntax

HTTP Requests

file_get_contents,
stream_get_contents,
and stream_context_create.

1. File: HTTP GET and Post Requests
2. File: Proxy Servers

cURL HTTP Requests

1. cURL: HTTP GET and POST Requests
2. cURL: HTTP Request Headers
3. cURL: HTTP HEAD Request
4. cURL: HTTP Response Headers
5. cURL: Proxy Servers

HTTP Headers and Redirects

1. Sending HTTP Headers
2. Redirecting Pages