PHP two-dimensional array is passed to js problem solving record_PHP tutorial

php two-dimensional array is passed to js problem solving record

Requirements:

php reads the two-dimensional array from the database and passes it to js

Implementation steps:

php:json_encode → json → js:eval

That is, use json_encode() in php to convert the php two-dimensional array into json format, pass it to js, ​​and use eval() to parse to get the js two-dimensional array.

Code:

php:

<?php  
header("Content-Type: text/html; charset=utf8") ;
$con=mysqli_connect("url","name","password","databasename");
// Check connection
if (mysqli_connect_errno($con))
    echo "Failed to connect to MySQL: " . mysqli_connect_error();

mysqli_query($con,"set character set &#39;utf8&#39;");
mysqli_query($con,"set names &#39;utf8&#39;");

$json_arr = array(array("a","b","c",1,2,3),array("q","w",1,2));
$jsonstr = json_encode($json_arr);

?>
var json=<?=$jsonstr?>;

<script type="text/javascript" src="http://.../test.php"></script>
<script language="javascript" type="text/javascript">	    
	$(document).ready(function(){
	    var jsonstr =eval(json);
	    for(var k=0;k<jsonstr.length;k++){
               for(var i=0;i<jsonstr[k].length;i++)
                  alert(jsonstr[k][i]);
            }
        })
</script>

Problems encountered:

1. When the two-dimensional array in php is converted into json using json_encode(), the second-dimensional array can be echoed out, but the converted json is empty.

Check the information online to determine that the problem is that the second-dimensional array contains non-utf8 encoding. Sure enough, I swapped the positions of the second-dimensional array in the two-dimensional array, and the json of the first array became empty.

Conclusion: json_encode() can convert multi-dimensional arrays, but the basic requirement is to encode it into utf8. When a sub-array in a multi-dimensional array is converted from json to null, it is very likely that this sub-array contains elements whose encoding is not utf8.

2.wamp mysql In phpmyadmin, I see that the content of the data table is normal Chinese characters, but when I read it and print it with php, I found that the Chinese characters have changed? .

The organization method of each table in the database is utf8_general_ci, which is also declared in the php file

header("Content-Type: text/html; charset=utf-8") ;
...
mysqli_query($con,"set character set 'utf-8'");
mysqli_query($con,"set names 'utf-8'");

It should be like this:

header("Content-Type: text/html; charset=utf8") ;
...
mysqli_query($con,"set character set 'utf8'");
mysqli_query($con,"set names 'utf8'");