Description
Adds the string value to the head (left) of the list. Creates the list if the key didn't exist. If the key exists and is not a list, FALSE is returned.
添加一个字符串值到LIST容器的顶部（左侧），如果KEY不存在，曾创建一个LIST容器，如果KEY存在并且不是一个LIST容器，那么返回FLASE。
Parameters
key
value String, value to push in key
Return value
LONG The new length of the list in case of success, FALSE in case of Failure.
返回LIST容器最新的长度，如果ADD成功。失败则返回FALSE。
Examples
$redis->delete('key1');
$redis->lPush('key1', 'C'); // returns 1
$redis->lPush('key1', 'B'); // returns 2
$redis->lPush('key1', 'A'); // returns 3
/* key1 now points to the following list: [ 'A', 'B', 'C' ] */