局限三有问题。"hello" instanceof String.class 也没这种用法啊，应该是"hello" instanceof String

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#1 Created at ... [Delete] [Delete and Lock User]

p instanceof Pair<String>.class

p instanceof Pair<Integer> //可以的

#2 Created at ... [Delete] [Delete and Lock User]

是

p instanceof Pair<Integer>

无法编译

#3 Created at ... [Delete] [Delete and Lock User]

我发现jdk14下面可以写p instanceofPair<Integer>，而jdk8只能写p instanceofPair

Pair<Integer> p = new Pair<>(123, 456);

if (p instanceof Pair<Integer>) {

System.out.println(true);

}

#4 Created at ... [Delete] [Delete and Lock User]

可以编译的p instanceof Pair<Integer>和p instanceof Pair 都可以

p instanceof Pair<String> 编译会出错

#5 Created at ... [Delete] [Delete and Lock User]

你都知道了p是Pair<Integer>后面再判断有什么意义？

Pair<Integer> p = ...
if (p instanceof Pair<Integer>) {
   ...
}

如果你不知道p的类型又编译不过：

Object p = ...;
if (p instanceof Pair<String>) { // compile error
}

所以instanceof根本无法判断带泛型的类型