Summary of 11 classic PHP interview questions and answers (share)

This article will share with you 11 classic PHP interview questions and answers. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

# Classic PHP Programmer Interview Questions

1. What does PHP mean? What can it do?

PHP is a server-based scripting language for creating dynamic websites. You can use PHP and HTML Generate the website homepage, the full name in English (Professional Home Pages)

(1)WEB development, order fulfillment, network communication, online payment, and all the work that the Internet can achieve.

(2) Script development, Shell scripts, Windows scheduled tasks, etc.

(3) Software development, PHP-GTK and other third-party software, use PHP syntax to cooperate with other languages ​​to develop software

2. Talk about your understanding of mvc?

Application completed by Model, View, and Controller

3. What is the GD library used for?

The GD library provides a series of functions for processing images. You can use the GD library to process images or generate images. On websites, the GD library is usually used to generate thumbnails or to add watermarks to images or to generate reports on website data. The commonly used GD2 now has more powerful functions and can process gif and png images.

##4. The meaning of data type (int char varchar datetime text); What is the difference between varchar and char?

int is a numeric type, char fixed length string, varchar actual length string, datetime date and time type, text text string, the char location is fixed to the length set by the creation table, and varchar is variable Length of characters

5. What is the difference between the get and post submission methods in the form?

get is to send a request through the HTTP protocol and receive it by passing the url parameter

And post is entity data, which can submit a large amount of information through a form.

6. What is the difference between session and cookie?

session: stores the global unique variable visited by the user. The general

stored in the directory specified by PHP on the server is used in the background and in places with high security. Cookie: It is stored on the client side. For cookies, it is stored under the user's browser. Generally, users

log in, where the load pressure is relatively high. Can reduce the load on the server.

7. What are the differences between echo(), print(), and print_r()?

echo is a PHP statement, print and print_r are functions, and the statements have no return value. Functions can have return values. print() can only print out the values ​​of simple type variables (such as int, string)

print_r() can print out the values ​​of complex type variables (such as arrays, objects)

Echo outputs one or more strings

8. What is template technology, a template that can be used separately from HTML and PHP?

Template technology is to use PHP is separated from HTML, CSS, and JS to achieve more reasonable code deployment Smarty, XTemplate, Template Lite, Easy Template…

9. What tools are used for version control?

Cvs, Svn, Vss

10. What method do you use for high-traffic websites? Solve the traffic problem?

Confirm whether the server hardware is sufficient to support the current traffic, separate database reading and writing, optimize data tables,

Program function rules, prohibit external hot links, control For downloading large files, use different hosts to divert the main traffic

(1) PHP programs can use generated static files to achieve service database pressure

(2) Use PHP caching technology, or third-party To achieve server pressure with caching technologies such as mamcached, refer to "PHP100 Video Tutorial" samrty caching technology, mamcached caching usage

11. What is the difference between include and require? What can be used to replace them to avoid including the same file multiple times? ?

require is fatal when the included file does not exist or has a syntax error. include is not require and needs to be placed in the header to be loaded in advance, while include is placed anywhere in the file and loaded at any time

There is also a pair of extension functions: require_once() include_once()

Recommended learning: "

PHP Video Tutorial

"

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