Php high-level programmer interview questions

Welcome to the Linux community forum and interact with 2 million technicians. 1. What is the difference between single quotation marks and double quotation marks in php? Which is faster? Why? (Basic php skills) 2. directly exchange the existing two variable values without new variables. (Test php basic skills) 3. Convert the PHP numeric amount to the size format, and explain the ideas (test the array) 4. SQL

Welcome to the Linux community forum and interact with 2 million technical staff> 1. What is the difference between single quotation marks and double quotation marks in php? Which is faster? Why? (Basic php skills) 2. directly exchange the existing two variable values without new variables. (Test php basic skills) 3. Convert the PHP numeric amount to the size format, and explain the ideas (test the array) 4. SQL

Welcome to the Linux community forum and interact with 2 million technicians>

1. Which speed is the difference between single quotes and double quotes in php faster? Why? (Test Basic php skills)

2. There is no need for new variables to directly swap the existing two rational values. (Test Basic php skills)

3. Convert the PHP numeric amount to the size format and describe the ideas (test the array)

4. the SQL query statement is as follows:

Select * from table where (ID = 10) or (ID = 32) or (ID = 22) or (ID = 76) or (ID = 13) or (ID = 44)

Let the results be retrieved in the order of 10, 32,. How can I write it? (SQL capability)

5. A simple File Upload program requires that the number of files uploaded at the same time be manually controlled (logical capability)

6. php simultaneously calls the information of one table in three databases (set up. a. aid = B. b. bid = C. c. cid). Describe your ideas and write some code.

7. An IM software is available. The id and email are used as registration conditions. Assume that 1040 people have been registered, there is a zh_cn forum, and id and email are used as registration conditions. Assume that 200 people have been registered, there is an en_us forum where id and email are used as registration conditions. Assume that you have registered 150 people.

Requirement: Synchronize the three, use the unified registration process, and write the design ideas

8. a. Write a script, analyze apache access. log, and obtain the top five files with the highest access volume (Unix/Apache)

B. Create a database with a table (see the following figure) and authorize it to all users in the 192.168.1. * network segment.

Table requirements: daily file access, including file name, access IP address, access time, client browser name, consider

How to efficiently find the maximum traffic volume during each day

C. Configure the Operating System (FreeBSD/Linux) so that it can execute the script to start apache and mysql after it is started into the operating system.