Summary of issues that PHP programmers must know, summary for PHP programmers_PHP tutorial

A summary of issues that PHP programmers must know, a summary of PHP programmers

Are you looking for a PHP development job and looking for some PHP interview questions and answers? This article shares with you some of the 11 most frequently asked PHP interview questions, as well as the corresponding common answers. Each company has its own interview standards. The interview and questions completely depend on the role you play in the job. Of course It is also closely related to your programming skills.

1. Question: Please tell me what PHP is in the simplest language?
Answer: The full name of PHP: Hypertext Preprocessor, is a server scripting language used to develop dynamic websites.

2. Question: What is MVC?
Answer: MVC consists of Model, View and Controller. PHP MVC can manage PHP code in three different layers more efficiently.

Model: Data information access layer.

View: The view layer is responsible for displaying application data on the interface in a specific way.

Controller: Usually the controller is responsible for reading data from the view, controlling user input, and sending data to the model.

3. Question: How many ways are there to reference CSS in the page?
Answer: There are 3 ways to use CSS in the page:

Reference external CSS files
Internally defined Style
Inline styles

4. Question: Does PHP support multiple inheritance?
Answer: No. PHP classes can only inherit from one parent class and are identified with the keyword "extended".

5. Question: What is the difference between echo and print in PHP?
These two look similar in that they both print some value to the screen. But the essential difference between echo and print is that echo is used to output a string, and multiple values ​​can be separated by commas when displaying them. Only basic types are supported. Print can not only print string values, but also print function return values.

6. Question: What is the difference between GET and POST methods?
Answer: The form information we fill in on the web page can pass the data to the server through these two methods. When we use the GET method, all the information will appear in the URL address, and using the GET method can only pass 1024 at most. characters, so the GET method can be used if the transmission volume is small or security is not so important. Speaking of the POST method, up to 2MB bytes of data can be transferred and can be adjusted as needed.

7. Question: What is the method to get the image size in PHP?
Answer: getimagesize () gets the size of the image

Imagesx () gets the width of the image

Imagesy () gets the height of the image

8. Question: What is PEAR in PHP?
Answer: PEAR is PHP Extension and Application Repository, which is a code repository for PHP extensions and applications.

9. Question: How to upload videos using PHP and MySQL?
Answer: We can store the address of the video in the database without storing the real video data in the database. Video data can be stored in a specified folder on the server. The default upload size is 2MB, but we can also change it by modifying the max_file size option in the php.ini file.

10. Question: What are the error types in PHP?
Answer: There are roughly three types of errors encountered in PHP.

Tips: These are very normal messages, not major errors, and some will not even be displayed to users. For example, access a variable that does not exist.

Warning: This is a serious error. A warning message will be displayed to the user, but it will not affect the output of the code, such as including some non-existent files.

Errors: These are really serious errors, like accessing a non-existent PHP class.

11. Question: How to define constants in PHP?
Answer: Define () is used in PHP to define constants.

define (“Newconstant”, 30);

Question: How to submit a form without using the submit button?
If we don’t want to use the submit button to submit the form, we can also use a hyperlink to submit. We can write the code like this:

Submit Me

The above 11 are considered the most basic PHP common sense. I will record them here and give them a reference for new PHPers