小编lea*_*ock的帖子

初学者QQ：我有一个列表和一个Map。我需要对照“列表”检查“地图”中的所有值，如果该值在地图中但不在列表中，那么我需要将其删除

    List<String> list = getRequiredList();
    Set<String> set = new HashSet<>(list)
    Map<String, String> map = getMap(); 

需要一些有关如何从地图中删除（如果不在列表中）的信息

I want to add a null check to my ternary operator which checks on a Boolean isValue:

public String getValue() {
    return isValue ? "T" : "F";
}

My task is:

What if the Boolean(object) return null? Add a boolean check and return "" (empty String in case if its null).

Note that isValue is a Boolean, not boolean.