在
java中允许指定函数返回的类型,例如下面的代码
public class Test {
static class Dad {
Dad me() {
return this;
}
}
static class Son extends Dad {
Son me() {
return this;
}
}
}
已验证.
我们来看看ArrayList类.它已经覆盖了clone()函数(至少我看到它在Oracle jdk 1.7源代码)
public Object clone() {
try {
@SuppressWarnings("unchecked")
ArrayList v = (ArrayList) super.clone();
v.elementData = Arrays.copyOf(elementData, size);
v.modCount = 0;
return v;
} catch (CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new InternalError();
}
}
什么是不返回ArrayList< E>但只是对象？
