Summary of written test questions in PHP interview questions

In our previous courses, we have introduced php interview questions about thinkphp, and 2017's most complete PHP interview questions and answers summary, many of which PHP interview questions are in There are many oral and written PHP interview questions. Today we will summarize them for you!

Written test in php interview questions

1. Use PHP to write the display customer Code of client IP and server IP

Answer: Print client

IP:echo $_SERVER['REMOTE_ADDR'];

or:

getenv('REMOTE_ADDR');

Print server IP:

echo gethostbyname('www.meizhi520.com')

2. What is the difference between session and cookie?

Answer: session: storage The global unique variable accessed by the user is stored in the directory (session_dir) specified by PHP on the server. Cookie: used to store continuous visits to a page. It is stored on the client. For cookies, it is Stored in the Temp directory of the user's WIN. Both can set the length of time through time

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

Answer: get is to send a request through the HTTP protocol through the url Parameters are passed for reception, and post is entity data, which can submit a large amount of information through the form.

4. Use PHP to print out the time of the previous day in the format of 2013-11-26 12:11:11

Answer:

echodate('Y-m-d H:i:s', strtotime('-1 days'));

5. Write a function that can traverse all files and subfolders in a folder. (Directory operation)

$d = dir(dirname(__file__));
echo "Handle: " . $d->handle . "\n";
echo "Path: " . $d->path . "\n";
while ( false !== ($entry = $d->read ()) ) {
echo $entry . "";
}
$d->close ();

6. Please write a function to verify whether the format of the email is correct

function checkEmail($email)
{
$pregEmail = "/([a-z0-9]*[-_\.]?[a-z0-9]+)*@([a-z0-9]*[-_]?[a-z0-9]+)+[\.][a-z]{2,3}([\.][a-z]{2})?/i";
return preg_match($pregEmail,$email);
}

7. Implement Chinese text string interception The gibberish-free approach.

function GBsubstr($string, $start, $length) {
    if(strlen($string)>$length){
        $str=null;
        $len=$start+$length;
        for($i=$start;$i<$len;$i++){
            if(ord(substr($string,$i,1))>0xa0){
                $str.=substr($string,$i,2);
                $i++;
            }else{
                $str.=substr($string,$i,1);
            }
        }
        return $str.&#39;…&#39;;
    }else{
        return $string;
    }
}

8. What is the redirection function of JS? How to introduce an external JS file?

window.location.href <script type="text/javascript" src="js/js_function.js"></script>

9. How to optimize the MySQL database?

Answer: (1) Configuration optimization (server configuration)

(2) Table creation optimization (table and field settings)

(3) Query optimization ( sql statement)

Answer: 1. Select the most applicable field attribute, reduce the length of the defined field as much as possible, and try to set the field to NOT NULL, such as 'province, gender', it is best to set it to ENUM

2. Use JOIN to replace subqueries:

3. Use UNION to replace manually created temporary tables

4. Transaction processing:

5. Lock the table and optimize transaction processing:

6. Use foreign keys to optimize the locking table

7. Create an index:

8. Optimize the query statement

10. How to use the following class and explain what it means?

class test{
    function Get_test($num){
        $num=md5(md5($num)."En");
        return $num;
    }
}

Answer:

$testnum = "123″; $object = new test(); $encrypt = $object->Get_test($testnum); echo $encrypt;

The class test contains the Get_test method, which is called when instantiating the class Method multi-string encryption

Summary:

Here we just summarize for you, what you will often encounter in PHP interview questions You can refer to the written test questions, and you can also expand on them to enhance your knowledge! Hope this helps!

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