PHP Tutorials - Herong's Tutorial Examples - Version 4.20, by Dr. Herong Yang
Returning Values from Functions
This section provides a tutorial example on how to return values from functions - using the 'return' statement.
PHP supports function return values with some basic rules:
To help us understand these rules, I wrote this tutorial example:
<?php # FunctionReturnValues.php #- Copyright (c) 2003-2019, HerongYang.com, All Rights Reserved. # date_default_timezone_set("Europe/Paris"); function returnType($arg) { if (is_null($arg)) return "NULL"; elseif (is_bool($arg)) return "BOOLEAN"; elseif (is_int($arg)) return "INTEGER"; elseif (is_float($arg)) return "FLOAT"; elseif (is_string($arg)) return "STRING"; elseif (is_array($arg)) return "ARRAY"; elseif (is_object($arg)) return "OBJECT"; elseif (is_resource($arg)) return "RESOURCE"; else return "UNKNOWN"; } print("\n Returning a scalar value:\n"); print(" 1: " . returnType(1) . "\n"); print(" 1.0: " . returnType(1.0) . "\n"); print(" array(1.0): " . returnType(array(1.0)) . "\n"); function createArray() { return func_get_args(); } print("\n Returning an array value:\n"); print(" createArray(): ".returnType(createArray(3,6,9))."\n"); function currentDate() { return new DateTime(); } print("\n Returning an object value:\n"); print(" currentDate(): " . returnType(currentDate()) . "\n"); function noReturn() { } print("\n Function without return statements:\n"); print(" noReturn(): " . returnType(noReturn(3,1,4)) . "\n"); ?>
If you run this sample script, you should get:
C:\herong> \php\php FunctionReturnValues.php Returning a scalar value: 1: INTEGER 1.0: FLOAT array(1.0): ARRAY Returning an array value: createArray(): ARRAY Returning an object value: currentDate(): OBJECT Function without return statements: noReturn(): NULL
Last update: 2019.
Table of Contents
Introduction and Installation of PHP 7.3
PHP Data Types and Data Literals
Variables, References, and Constants
Expressions, Operations and Type Conversions
Conditional Statements - "if" and "switch"
Loop Statements - "while", "for", and "do ... while"
►Function Declaration, Arguments, and Return Values
"function" Statements - Defining Functions
Passing Arguments to Functions
Example of Passing Arguments by Values
Using Pass-by-Value Arguments for References
Example of Passing Arguments by References
Variable-Length Argument Lists
Providing Default Values to Argument Variables
►Returning Values from Functions
Returning References from Functions
Introduction of Class and Object
Integrating PHP with Apache Web Server
Retrieving Information from HTTP Requests
Creating and Managing Sessions in PHP Scripts
Sending and Receiving Cookies in PHP Scripts
Controlling HTTP Response Header Lines in PHP Scripts
MySQL Server Connection and Access Functions
Functions to Manage Directories, Files and Images
SOAP Extension Function and Calling Web Services
SOAP Server Functions and Examples
Localization Overview of Web Applications
Using Non-ASCII Characters in HTML Documents
Using Non-ASCII Characters as PHP Script String Literals
Receiving Non-ASCII Characters from Input Forms
"mbstring" Extension and Non-ASCII Encoding Management
Managing Non-ASCII Character Strings with MySQL Servers