PHP Tutorials

Php What is
Php Syntax
Php Comments
Php Booleans
Php Integers
Php Floating point numbers
Php Strings
Php Variable
Php Identifiers
Php Constants
Php Expressions
Php Operator
Php Control structure
Php Array
Php Functions
Php Null
Php Include
Php Include once
Php Require
Php Require once
Php Predefined Variables
Php Predefined Functions

PHP INI Tutorials

Php ini What is
Php ini Language Options
Php ini Safe Mode
Php ini Miscellaneous
Php ini Resource limits
Php ini Error reporting
Php ini Display errors
Php ini Data Handling
Php ini Magic quotes
Php ini Path and Directorie
Php ini File Uploads
Php ini Fopen wrappers
Php ini Dynamic Extensions

php Identifiers

Identifier is a general term applied to variables, functions, and various other userdefined objects. There are several properties that PHP identifiers must abide by:

  • An identifier can consist of one or more characters and must begin with a letter or an underscore. Furthermore, identifiers can consist of only letters, numbers,underscore characters, and other ASCII characters from 127 through 255.
    • Valid Invalid
    my_function This&that
    Size !counter
    _someword 4ward
  • Identifiers are case sensitive. Therefore, a variable named $recipe is different from a variable named $Recipe, $rEciPe, or $recipE
  • Identifiers can be any length. This is advantageous because it enables a programmer to accurately describe the identifier's purpose via the identifier name
  • An identifier name can't be identical to any of PHP's predefined keywords. You can find a complete list of these keywords in the PHP manual appendix.



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