The most complete and detailed PHP interview questions (with answers)

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1. What does __FILE__ mean? (5 points)
The full path and file name of the file. If used in an include file, returns the include file name. As of PHP 4.0.2, __FILE__ always contains an absolute path, while previous versions sometimes contained a relative path.
2. How to obtain the client’s IP address? (5 points)

$_SERVER[‘REMOTE_ADDR’]

3. Write a statement that uses the header function to jump to the page (5 points)

Header(‘location:index.php’);

4. $str is a piece of html text, use Regular expression to remove all js scripts (5 points)

$pattern = ‘/<script.*>\.+<\/script>/’;
Preg_replace($pattern,’’,$str);

5. Write a statement to remove null values ​​​​in an array (5 points)

$arr = array(‘’,1,2,3,’’,19);

First method:

$array1 = array('  ',1,'',2,3);
print_r(array_filter($array1, "del"));
function del($var)
{
       return(trim($var)); 
}

Second method:

$arr=array("",1,2,3,"");
$ptn="/\S+/i";
print_r(preg_grep($ptn,$arr));

6. Write a function to obtain the current timestamp and a method to print the time of the previous day (Format: Year-Month-Day Hour:Minute:Second) (5 points)

Time();
Date(“Y-m-d H:i:s”,Strtotime(“-1 day”));

7. Write the function for encoding conversion in PHP (5 points)

Iconv(‘utf-8’,’gb2312’,$str);

8, $str = "1,3,5,7,9,10,20", what function can be used to convert the string str into an array containing each number? (5 points)

$arr = explode(“,”,$str);

9. The role of the serialize() /unserialize() function (5 points)
The explanation of serialize() and unserialize() in the PHP manual is:
serialize — Generates a representation of a storable value. The return value is a string. This string contains a byte stream representing value without losing its type and structure and can be stored anywhere.
unserialize — Create a PHP value from a stored representation
Specific usage:

$arr = array(“测试1″,”测试2″,”测试3″);//数组
$sarr = serialize($arr);//产生一个可存储的值(用于存储)

//Use any method (for example: if you save $sarr in a text file you You can use file_get_contents to get the stored value and save it in $newarr;

$unsarr=unserialize($newarr);//从已存储的表示中创建 PHP 的值

10. Write a function with the parameters as year and month, and the output result is the number of days in the specified month (5 points)

Function day_count($year,$month){
Echo date(“t”,strtotime($year.”-”.$month.”-1”));
}

11. The path of a file is /wwwroot/include/page.class.php. Write a method to obtain the file extension (5 points)

$arr = pathinfo(“/wwwroot/include/page.class.php”);
$str = substr($arr[‘basename’],strrpos($arr[‘basename’],’.’));

12. Which PHP template engine have you used? (5 points)
Smarty, the template engine that comes with thinkphp
13. Please simply write a class, instantiate this class, and write statements to call the properties and methods of the class (5 points)

Class myclass{
Public $aaa;
Public $bbb;
Public function myfun(){
Echo “this is my function”;
}
}
$myclass = new myclass();
$myclass->$aaa;
$myclass->myfun();

14. The table friend has been built in the local mysql database db_test. The database connection user is root and the password is 123
The friend table fields are: id, name, age, gender, phone, email
Please use php to connect to mysql, select all records with age > 20 in the friend table, print the results, and count the total number of query results. (5 points)

<?php
$link = Mysql_connect(“localhost”,”root”,”123”) or die(“数据库连接失败!”);
Mysql_select_db(“db_test”,$link) or die(“选择数据库失败!”);
$sql = “select id,name,age,gender,phone,email from friend where age>20”;
$result = mysql_query($sql);
$count = mysql_num_rows($result);
While($row = mysql_fetch_assoc($result)){
Echo $row[‘id’];
….
}

15. There are two tables below
user table field id (int), name (varchar)
score table field uid (int), subject (varchar) ), score (int)
The uid field of the score table is associated with the id field of the user table
Required to write the following sql statement
1) Insert a new record in the user table and insert it in the score table Two records associated with the newly added record (5 points)
2) Obtain the five records with the highest score for the user whose uid is 2 in the score table (5 points)
3) Use a joint query to obtain the name " The total score of the user named "李思" (5 points)
4) Delete the user named "李思", including the score record (5 points)
5) Clear the score table (5 points)
6 ) Delete the user table (5 points)

1). mysql_query(“insert into user(name) values(‘test’)”);
$id = mysql_insert_id();
Mysql_query(“insert into score(uid,subjext,score) values(“.$id.”,’english’,’99’)”);
2).$sql = select uid,sunjext,score from score where uid=2 order by score desc limit 0,5;
3).select s.score from score s RIGHT JOIN user u ON u.id=s.uid where u.name=’张三;
4).delete from score where uid in(select id from user where name=’李四’);
Delete from user where name=’李四’;
5).delete from score;
6).drop table user;

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