How to convert php json string to array

php How to convert json string to array: First use the "json_decode" function to encode the string in JSON format; then print "$students" through the "var_dump($students);" method.

Recommended: "PHP Video Tutorial"

php json string to array or object

The method found on the Internet is to use get_object_vars to convert the class type into an array and then use foreach to traverse it

$array = get_object_vars($test);
$json= '[{"id":"1","name":"\u5f20\u96ea\u6885","age":"27","subject":"\u8ba1\u7b97\u673a\u79d1\u5b66\u4e0e\u6280\u672f"},{"id":"2","name":"\u5f20\u6c9b\u9716","age":"21","subject":"\u8f6f\u4ef6\u5de5\u7a0b"}]';

First, use json_decode to encode the string in JSON format,

$students = json_decode($json);

Use $students directly in the PHP file:

for($i=0;$i<count($students);$i++){
         echo "姓名：".$students[$i][&#39;name&#39;]."年龄：".$students[$i][&#39;age&#39;]."专业：".$students[$i][&#39;subject&#39;]."<br/>";
    }

, the error will be reported as follows:

Fatal error
: Cannot use objectof type stdClass as array in 
D:\wamp\www\test.php
on line 
18

At this time, print $students:

var_dump($students);

will output:

array(2) {
        [0]=>
        object(stdClass)#2 (4) {
             ["id"]=> string(1)"1"
             ["name"]=> string(9)"张雪梅"
             ["age"]=> string(2)"27"
        object(stdClass)#3 (4) {                              这个就说明转换的json字符串转为对象而非数组,请看下面的红色背景字

["subject"]=>string(24) "计算机科学与技术"
        }
        [1]=>
            ["id"]=> string(1)"2"
            ["name"]=> string(9)"张沛霖"
            ["age"]=> string(2)"21"
           ["subject"]=> string(12) "软件工程"
        }
    }

It can be seen that the returned result is object instead of array. Should be accessed in object form:

foreach($students as $obj){
         echo "姓名：".$obj->name."年龄：".$obj->age."专业：".$obj->subject."<br/>";
    }

The output result is:

Name: Zhang Xuemei Age: 27 Major: Computer Science and Technology
Name: Zhang Peilin Age: 21 Major: Software Engineering

mixedjson_decode ( string$json [, bool$assoc ] )

Description: Accept a JSON format string and convert it Convert to PHP variable.

json_decode can receive two parameters:

json: the string in jsonstring format to be decoded.

assoc: When this parameter is TRUE, an array will be returned instead of an object.

 $students = json_decode($json,true);

Print $students at this time:

var_dump($students);

Output:

array(2) {
        [0]=>
        array(4) {
            ["id"]=> string(1)"1"
            ["name"]=> string(9)"张雪梅"
            ["age"]=> string(2)"27"
            ["subject"]=>string(24) "计算机科学与技术"
        }
        [1]=>
        array(4) {
           ["id"]=> string(1)"2"
           ["name"]=> string(9)"张沛霖"
           ["age"]=> string(2)"21"
           ["subject"]=>string(12) "软件工程"
        }
    }

At this time, $students is an array and can be used directly:

for($i=0;$i<count($students);$i++){
     echo "姓名：".$students[$i][&#39;name&#39;]."年龄：".$students[$i][&#39;age&#39;]."专业：".$students[$i][&#39;subject&#39;]."<br/>";
}

The output result is:

Name: Zhang Xuemei Age: 27 Major: Computer Science and Technology
Name: Zhang Peilin Age: 21 Major: Software Engineering

Summary:

Two methods to process JSON formatted strings in PHP code:

Method one:

$json= '[{"id":"1","name":"\u5f20\u96ea\u6885","age":"27","subject":"\u8ba1\u7b97\u673a\u79d1\u5b66\u4e0e\u6280\u672f"},{"id":"2","name":"\u5f20\u6c9b\u9716","age":"21","subject":"\u8f6f\u4ef6\u5de5\u7a0b"}]';
$students= json_decode($json);//得到的是 object
foreach($studentsas $obj){
    echo "姓名：".$obj->name."   年 龄：".$obj->age."   专 业：".$obj->subject."<br />";}

Method two:

$json= '[{"id":"1","name":"\u5f20\u96ea\u6885","age":"27","subject":"\u8ba1\u7b97\u673a\u79d1\u5b66\u4e0e\u6280\u672f"},{"id":"2","name":"\u5f20\u6c9b\u9716","age":"21","subject":"\u8f6f\u4ef6\u5de5\u7a0b"}]';
$students= json_decode($json, true);//得到的是 array
for($i=0;$i<count($students);$i++){    echo "姓名：".$students[$i][&#39;name&#39;]."   年 龄：".$students[$i][&#39;age&#39;]."   专 业：".$students[$i][&#39;subject&#39;]."<br />";

----------------------------------------- -------------------------------------------------- -------------------------------------

The above is the detailed content of How to convert php json string to array. For more information, please follow other related articles on the PHP Chinese website!