返回名称为 name
的第一个名称-值对的值。
如果没有这样的对,则返回 null
。
name
<string>
- Returns: <string> or
null
if there is no name-value pair with the given
name
.
Returns the value of the first name-value pair whose name is name
. If there
are no such pairs, null
is returned.