我有下面的JSON数组，并且我在一个惟一id对象中寻找一个特定的值。问题是，这个字段并不总是存在，因为它是一个字段外的对象。
我要找的是'Kn04'
{
"searchMeta": {
"maxResults": 100,
"sourceId": "6e5c1d5d-d84b-4b64-9d2c-a32b8c9f7174",
"iso8601Timestamps": true,
"sourceType": "VENUE",
"endTimestamp": 1444952156,
"startTimestamp": 1444952056
},
"ranges": [
{
"clients": [
{
"clientId": {
"mac": "6c:19:8f:bf:47:e9"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -93.3
}
]
},
{
"clientId": {
"uniqueId": "Kn04"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -75.3
}
]
},
{
"clientId": {
"mac": "58:6d:8f:75:95:0e"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -86.2
}
]
},
{
"clientId": {
"mac": "44:d9:e7:21:e0:de"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -25.8
}
]
},
{
"clientId": {
"mac": "68:72:51:10:e7:26"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -47
}
]
},
{
"clientId": {
"mac": "68:72:51:10:e7:29"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -72.3
}
]
},
{
"clientId": {
"mac": "a4:ee:57:2e:ac:bd"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -95
}
]
},
{
"clientId": {
"uniqueId": "CQos"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -64.1
}
]
},
{
"clientId": {
"mac": "86:8f:c2:8f:c3:20"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -68.4
}
]
},
{
"clientId": {
"mac": "32:91:8f:6c:2e:f4"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -87.7
}
]
},
{
"clientId": {
"mac": "30:91:8f:6c:2e:f3"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -86.9
}
]
},
{
"clientId": {
"mac": "30:91:8f:43:ca:49"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -87
}
]
},
{
"clientId": {
"mac": "1d:8b:90:7b:20:9c"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -102.5
}
]
},
{
"clientId": {
"mac": "38:2c:4a:5c:b6:a0"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -76.7
}
]
},
{
"clientId": {
"uniqueId": "ECgg"
},
"rssis": [
{
"sourceId": "zR1L3",
"value": -59.5
}
]
}
],
"timestamp": "2015-10-15T23:35:00+00:00"
}
]
}
到目前为止，我的代码如下，但它不起作用。$response是JSON数组名
$json = json_decode($response,true);
foreach($json['ranges'] as $range){
foreach($range['clients'] as $client)
foreach($client['clientId'] as $client1 => $device)
{
if($device['uniqueId'] == "Kn04")
{
echo $device=>uniqueId;
}
}}
首先，json_decode()将返回一个数组而不是一个对象，因为如果$assoc设置为true，返回的对象将被转换为关联数组。
mixed json_decode ( string $json [, bool $assoc = false [, int $depth = 512 [, int $options = 0 ]]] )
阅读本文档
在循环的这一层:
foreach($client['clientId'] as $client1 => $device)
$device已经指向了唯一id，所以不用:
if($device['uniqueId'] == "Kn04")
你只需要写:
if($device== "Kn04")
我不明白你为什么要显示uniqueId的值也就是Kn04，因为你知道它，所以也许不用那样:
echo $device;
添加所有函数并返回true或false响应
$json = json_decode($response, true);
function findDevice($id) {
global $json;
foreach($json['ranges'] as $range) {
foreach($range['clients'] as $client) {
foreach($client['clientId'] as $client1 => $device) {
if($device==$id) return true; // or return sthing else
}
}
}
return false;
}
这里有一个递归函数可以使用。递归搜索很酷的一点是它不关心数组结构。如果之后出现更多关卡，你就不需要更改任何内容。另外，我不明白你为什么要打印已知的id所以在我的例子中，它打印了整个设备
$json = json_decode($response,true);
function findRecursive($array, $needle){
if(is_array($array)){
foreach($array as $key => $item){
if($item === $needle){
return $array;
}
$found = findRecursive($item, $needle);
if($found != false){
return $found;
}
}
} else return false;
}
$device = findRecursive($json, 'Kn04');
if($device) {
print_r($device);
} else {
echo "Not found";
}
$json = json_decode($response,true);
function matchSidsByThresholdRecursive($array, $treshold, &$results){
if(is_array($array)){
//If this is the array we are looking for - it has to have both 'sourceId' and 'value' indexes
if(isset($array['sourceId']) && isset($array['value'])){
//The current value is greater than threshold? Add the corresponding sourceId to results
if($array['value'] > $treshold){
$results[] = $array['sourceId'];
}
}
//If one of the subitems is an array - iterate through it the same way
foreach($array as $item){
if(is_array($item)){
matchSidsByThresholdRecursive($item, $treshold, &$results);
}
}
}
}
$results = array();
//This will populate the $results array with sourceIds with the values greater than -50
matchSidsByThresholdRecursive($json, -50, $results);
if($results) {
print_r($results);
} else {
echo "Not found";
}