PHP Frequently Asked questions resolved

This article introduces the content of the PHP common problems solved, has a certain reference value, now share to everyone, the need for friends can refer to

problem

Display Chinese garbled?

Solve

Modify the source file to a UTF-8 format.

problem

Uncaught Error: Cannot use string offset as an array in...

cause

The array to be written does not exist and needs to be created

$arrays = $array ();

problem

Set $_SESSION a variable to disappear after a page jump?

Solve

You need to $_SESSION call session_start(); it every time you use it.

problem

• After using the AJAX access server, the URL bar adds a?

• Open chrome , press F12 Enter the source code, set a breakpoint, the program does not jump into the breakpoint, but re-refresh the page?

Solve

When using a form, you need to use:

<form>    <label> Controller Debug Assistant:</label>    <input type= "button" Name= "Submit_xghelper" value= "Download "  onclick=" Ondownloadbuttonclick (' Xghelper ') "></form>

This format, if modified to:

<form>    <label> Controller Debug Assistant:</label>    <button onclick= "Ondownloadbuttonclick (' Xghelper ')" > Downloads </button></form>

The above situation will occur!

problem

PHPSend JS the JSON format data, JS JSON.parse() when using parsing, chrome prompt:

Uncaught syntaxerror:unexpected token? In JSON @ position 0 at    Json.parse (<anonymous>) at    XMLHttpRequest.xmlhttp.onreadystatechange ( download.php:84)

cause

File format error

Solve

Because of the background PHP file, use:

Require_once ". /utils/config.php ";

Contains other files, the file format is: UTF-8 with BOM , you need to Ultra Edit save the file as a UTF-8 format without BOM !

problem

Display Chinese garbled?

Solve

Modify the source file to a UTF-8 format.

problem

Uncaught Error: Cannot use string offset as an array in...

cause

The array to be written does not exist and needs to be created

$arrays = $array ();

problem

Set $_SESSION a variable to disappear after a page jump?

Solve

You need to $_SESSION call session_start(); it every time you use it.

problem

• After using the AJAX access server, the URL bar adds a?

• Open chrome , press F12 Enter the source code, set a breakpoint, the program does not jump into the breakpoint, but re-refresh the page?

Solve

When using a form, you need to use:

<form>    <label> Controller Debug Assistant:</label>    <input type= "button" Name= "Submit_xghelper" value= "Download "  onclick=" Ondownloadbuttonclick (' Xghelper ') "></form>

This format, if modified to:

<form>    <label> Controller Debug Assistant:</label>    <button onclick= "Ondownloadbuttonclick (' Xghelper ') ) "> Download </button></form>

The above situation will occur!

problem

PHPSend JS the JSON format data, JS JSON.parse() when using parsing, chrome prompt:

Uncaught syntaxerror:unexpected token? In JSON @ position 0 at    Json.parse (<anonymous>) at    XMLHttpRequest.xmlhttp.onreadystatechange ( download.php:84)

cause

File format error

Solve

Because of the background PHP file, use:

Require_once ". /utils/config.php ";

Contains other files, the file format is: UTF-8 with BOM , you need to Ultra Edit save the file as a UTF-8 format without BOM !