php中json_encode和json_decode的用法

1.json_encode基本用法：数组转字符串

<?php
$arr = array ('a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5);
echo json_encode($arr);
?>
以上例程会输出：
{"a":1,"b":2,"c":3,"d":4,"e":5}

 2.json_decode基本用法：字符串转数组

<?php
$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
var_dump(json_decode($json));
?>
输出
array{
["a"] => int(1)
["b"] => int(2)
["c"] => int(3)
["d"] => int(4)
["e"] => int(5)

3.json_encode在输出汉字的时候会被转义

$arr4 = array('t1'=>'测试下中文汉字','t2'=>'www.jd.com','t3'=>'123456789','t4'=>"!@#$%^&*",'t5'=>'汉字+www.jd.com+465454');
print_r(json_encode($arr4));exit;

输出结果：（汉字都会被转义）

{"t1":"\u6d4b\u8bd5\u4e0b\u4e2d\u6587\u6c49\u5b57","t2":"www.jd.com","t3":"123456789","t4":"!@#$%^&*","t5":"\u6c49\u5b57+www.jd.com+465454"}

4.如何保证json_encode不被转义

$arr5 = array('t1'=>urlencode('测试下中文汉字'));    // 重点1
print_r(urldecode(json_encode($arr5)));            // 重点2

输出结果：

{"t1":"测试下中文汉字"}

5.urlencode，json_encode,urldecode使用

$arr6 = urlencode('测试下中文汉字');
print_r($arr6);
print_r(json_encode($arr6));
print_r(urldecode($arr6));
print_r(urldecode(json_encode($arr6)));

输出结果：

%E6%B5%8B%E8%AF%95%E4%B8%8B%E4%B8%AD%E6%96%87%E6%B1%89%E5%AD%97       // $arr6 输出
"%E6%B5%8B%E8%AF%95%E4%B8%8B%E4%B8%AD%E6%96%87%E6%B1%89%E5%AD%97"    // json_encode输出
测试下中文汉字                                                             // urldecode输出结果
"测试下中文汉字"                                                          // urldecode+json_encode输出结果

6.Jquery调取php的json_encode内容

php代码

$arr = Array
(
    [goods_id] => 1
    [goods_sn] => LX000000
    [goods_name] => 保税区直发 德国Aptamil爱他美婴幼儿配方奶粉Pre段800g 【2罐起发】
)
echo json_encode($arr)

输出格式

{"id":"1","user_id":"1","goods_id":"1","goods_stock":"6","goods_sn":"LX000000","shop_price":168}

js输出json格式内容

function t(n,v){
    res = Ajax.call('user.php?act=depot_id', 'id=1',null,"GET", "JSON",false);

    var goods_title = "#goods_title_"+n;
    var goods_name = "#goods_name_"+n;
    var goods_price = "#goods_price_"+n;

    $(goods_title).val(res.goods_title);
    $(goods_name).val(res.goods_name);
    $(goods_price).val(res.goods_price);

    alert(res.goods_name);
    //document.getElementById(div).value = '11';
}

 7.json_decode 有stdClass Object，解决办法json_decode($s,true)，

$s = '[{"goods_id":"2","goods_num":2,"goods_name":"u8377u5170Nutrilonu725bu680fu5976u7c89 u30102u7f50u8d77u53d1u3011"},{"goods_id":"2","goods_num":2,"goods_name":"u8377u5170Nutrilonu725bu680fu5976u7c89 u30102u7f50u8d77u53d1u3011"}]';

f=jsondecode( s);

输出：

Array
(
    [0] => stdClass Object
        (
            [goods_id] => 2
            [goods_num] => 2
            [goods_name] => u8377u5170Nutrilonu725bu680fu5976u7c89 u30102u7f50u8d77u53d1u3011
        )

    [1] => stdClass Object
        (
            [goods_id] => 2
            [goods_num] => 2
            [goods_name] => u8377u5170Nutrilonu725bu680fu5976u7c89 u30102u7f50u8d77u53d1u3011
        )

)

解决办法：

f=jsondecode( s,true);
print_r($f);

输出：

Array
(
    [0] => Array
        (
            [goods_id] => 2
            [goods_num] => 2
            [goods_name] => u8377u5170Nutrilonu725bu680fu5976u7c89 u30102u7f50u8d77u53d1u3011
        )

    [1] => Array
        (
            [goods_id] => 2
            [goods_num] => 2
            [goods_name] => u8377u5170Nutrilonu725bu680fu5976u7c89 u30102u7f50u8d77u53d1u3011
        )

)

8.json汉字被转义 JSON_UNESCAPED_UNICODE 最简单方法

return json_encode($arr, JSON_UNESCAPED_UNICODE);   //  php 5.3以上版本可以使用 （JSON_UNESCAPED_UNICODE）

转自：http://www.cnblogs.com/wesky/p/4590953.html