以下是api获取的数据，怎么获取到第一组数据呢？只要一组
也就是20151224084:{number:9,7,6,8,0,dateline:2015-12-24 20:02:55}这个。
{20151224084:{number:9,7,6,8,0,dateline:2015-12-24 20:02:55},20151224083:{number:4,2,7,5,1,dateline:2015-12-24 19:52:55},20151224082:{number:6,5,5,5,7,dateline:2015-12-24 19:43:36},20151224081:{number:3,8,6,0,8,dateline:2015-12-24 19:33:01},20151224080:{number:5,1,6,7,9,dateline:2015-12-24 19:23:01},20151224079:{number:3,8,0,3,5,dateline:2015-12-24 19:13:05},20151224078:{number:1,2,2,8,4,dateline:2015-12-24 19:02:57},20151224077:{number:1,4,9,1,1,dateline:2015-12-24 18:52:58},20151224076:{number:3,2,4,0,3,dateline:2015-12-24 18:43:25},20151224075:{number:0,3,2,9,7,dateline:2015-12-24 18:32:59}}

回复内容： 以下是api获取的数据，怎么获取到第一组数据呢？只要一组
也就是20151224084:{number:9,7,6,8,0,dateline:2015-12-24 20:02:55}这个。
{20151224084:{number:9,7,6,8,0,dateline:2015-12-24 20:02:55},20151224083:{number:4,2,7,5,1,dateline:2015-12-24 19:52:55},20151224082:{number:6,5,5,5,7,dateline:2015-12-24 19:43:36},20151224081:{number:3,8,6,0,8,dateline:2015-12-24 19:33:01},20151224080:{number:5,1,6,7,9,dateline:2015-12-24 19:23:01},20151224079:{number:3,8,0,3,5,dateline:2015-12-24 19:13:05},20151224078:{number:1,2,2,8,4,dateline:2015-12-24 19:02:57},20151224077:{number:1,4,9,1,1,dateline:2015-12-24 18:52:58},20151224076:{number:3,2,4,0,3,dateline:2015-12-24 18:43:25},20151224075:{number:0,3,2,9,7,dateline:2015-12-24 18:32:59}}

array_shift();$json = '{20151224084:{number:9,7,6,8,0,dateline:2015-12-24 20:02:55},20151224083:{number:4,2,7,5,1,dateline:2015-12-24 19:52:55},20151224082:{number:6,5,5,5,7,dateline:2015-12-24 19:43:36},20151224081:{number:3,8,6,0,8,dateline:2015-12-24 19:33:01},20151224080:{number:5,1,6,7,9,dateline:2015-12-24 19:23:01},20151224079:{number:3,8,0,3,5,dateline:2015-12-24 19:13:05},20151224078:{number:1,2,2,8,4,dateline:2015-12-24 19:02:57},20151224077:{number:1,4,9,1,1,dateline:2015-12-24 18:52:58},20151224076:{number:3,2,4,0,3,dateline:2015-12-24 18:43:25},20151224075:{number:0,3,2,9,7,dateline:2015-12-24 18:32:59}}';$data = json_decode($json,true);// 方法1$want = $data['20151224084']; // 方法2$want = array_pop(array_reverse($data,true));// 最笨的办法$want = [];foreach($data as $key=>$value){ $want = [$key=>$value]; break;}
说明一下：第二种方式有个坑，就是当数组的长度特别长时，比如1000、10000，数组的翻转是一件很消耗性能的操作，所以，根据你的实际情况借鉴性的使用，第三种方式虽然笨，但是性能不错。
经友情提醒，刚才忘记了array_shift
json_decode($string, true)
转为数组后你肯定会了。