{"id":1037,"date":"2021-04-11T01:38:55","date_gmt":"2021-04-11T01:38:55","guid":{"rendered":"https:\/\/phptutorial.net\/?page_id=1037"},"modified":"2021-05-21T13:07:45","modified_gmt":"2021-05-21T13:07:45","slug":"php-throw-exception","status":"publish","type":"page","link":"https:\/\/www.phptutorial.net\/php-oop\/php-throw-exception\/","title":{"rendered":"PHP throw Exception"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you will learn about the Exception class in detail and how to throw a new exception in PHP.<\/p>\n\n\n\n

Introduction to the Exception class #<\/a><\/h2>\n\n\n\n

When encountering a situation from which you cannot recover, you can throw an exception.<\/p>\n\n\n\n

An exception is an instance of the Exception<\/code> class. Like other PHP objects, you use the new<\/code> keyword to create an instance of the Exception<\/code> class. <\/p>\n\n\n\n

An Exception<\/code> object has two main properties: a message and a numeric code. The message describes the exception. The numeric code is optional, which specifies the context for a specific exception.<\/p>\n\n\n\n

When you create a new exception, you provide the mesage the optional numeric code. For example:<\/p>\n\n\n

<?php<\/span>\n\n$exception = new<\/span> Exception<\/span>('Invalid username or password'<\/span>, 100<\/span>);<\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
The Exception<\/code> object has the getMessage()<\/code> and getCode()<\/code> that returns the message and numeric code:<\/p>\n\n\n
<?php<\/span>\n\n$exception = new<\/span> Exception<\/span>('Invalid username or password'<\/span>, 100<\/span>);\n\n$message =  $exception->getMessage();\n$code =  $exception->getCode();<\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
The throw statement #<\/a><\/h2>\n\n\n\n
In practice, you rarely assign an exception to a variable<\/a>. Instead, you raise (or throw) the Exception<\/code> object using the throw<\/code> statement:<\/p>\n\n\n
<?php<\/span>\n\nthrow<\/span> new<\/span> Exception<\/span>('Invalid username or password'<\/span>, 100<\/span>);<\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
When PHP encounters a throw<\/code> statement, it immediately halts the code execution. Therefore, the code after the throw statement won’t execute.<\/p>\n\n\n\n
Throwing an exception example #<\/a><\/h3>\n\n\n\n
The following example defines a function called divide()<\/code> that uses the the throw statement:<\/p>\n\n\n
function<\/span> divide<\/span>($x, $y)<\/span>\n<\/span>{\n    if<\/span> (!is_numeric($x) || !is_numeric($y)) {\n        throw<\/span> new<\/span> InvalidArgumentException('Both arguments must be numbers or numeric strings'<\/span>);\n    }\n\n    if<\/span> ($y == 0<\/span>) {\n        throw<\/span> new<\/span> Exception<\/span>('Division by zero, y cannot be zero'<\/span>);\n    }\n    return<\/span> $x \/ $y;\n}<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
How the define()<\/code> function works.<\/p>\n\n\n\n
The throw<\/code> statement accepts an instance of the Exception<\/code> class or the subclass of the Exception<\/code> class. In fact, it accepts any object that implements the Throwable<\/a><\/code> interface. Note that the Exception<\/code> class also implements the Throwable<\/code> interface.<\/p>\n\n\n\n