Upgrading to PHP 7

Table of contents

1. 1. Upgrading to PHP 7
   1. PHP 7 Timeline
   2. How We Got Here
   3. Release Cycle
2. 2. Deprecated Features
   1. Alternative PHP Tags
   2. POSIX-Compatible Regular Expressions
      1. Migrating to Perl Compatible Regular Expressions
   3. Multiple Default Cases in Switches
   4. Removal of the Original MySQL Extension
      1. Migrating to Procedural mysqli
      2. Migrating to an Object-Oriented API
      3. Using Mysqli
   5. Summary
3. 3. Uniform Variable Syntax
   1. Consistency Fixes
   2. New Syntax
      1. New Combinations
      2. Nested double colons
      3. Nested Method and Function Calls
      4. Arbitrary Expression Dereferencing
   3. Dereferencing scalars
   4. Future Syntax
   5. Backward Compatibility Issues
   6. Summary
4. 4. Basic Language Changes
   1. Operators
      1. Null Coalesce Operator
      2. Combined Comparison Operator
   2. Constant Arrays
   3. Unpacking Objects Using list()
   4. New Functions
      1. Integer Division
   5. Regular Expressions
   6. Cryptographically Secure Values
   7. Function Changes
      1. Sessions
   8. Filtered unserialize()
   9. Move Up Multiple Levels with dirname()
   10. Salts Deprecated in password_hash()
   11. Summary
5. 5. Expectations and Assertions
   1. Expectations
   2. Summary
6. 6. Error Handling
   1. Exceptions on Constructor Failure
   2. Engine Exceptions
      1. Exception Hierarchy
   3. Error Exceptions
      1. \Error
      2. \AssertionError
      3. \ArithmeticError and \DivisionByZeroError
      4. \ParseError
      5. \TypeError
   4. Catchable Fatal Errors
   5. \Throwable and Userland
   6. Calling Methods on non-objects
   7. Summary
7. 7. Unicode Enhancements
   1. Unicode Codepoint Escape Syntax
   2. New Internationalization Features
   3. Working with Unicode Characters
   4. Summary
8. 8. Closure Enhancements
   1. Bind Closure On Call
   2. Summary
9. 9. Generator Enhancements
   1. Generator Return Values
   2. Generator Delegation
   3. Summary
10. 10. Changes in Object-Oriented Programming
    1. Context-Sensitive Lexer
    2. PHP 4 Constructors Deprecated
    3. Group Use Declarations
    4. Anonymous Classes
    5. Anonymous Class Names
    6. Summary
11. 11. Type Hints
    1. Scalar Type Hints
       1. Coercive Types
       2. Precision Loss
       3. Strict Types
    2. Return Type Hints
    3. Reserved Keywords for Future Types
    4. Summary
12. A. Resources
    1. Further Reading
    2. Other Resources
13. B. RFCs for PHP 7.0
    1. Deprecated Features
    2. Uniform Variable Syntax
    3. Basic Language Changes
       1. Other RFCs
    4. Expectations and Assertions
    5. Error Handling
       1. Other RFCs
    6. Unicode Enhancements
    7. Closures
    8. Generators
    9. Object-Oriented Programming
    10. Type Hints
    11. Internals Changes