比较 Java 中的整数数组.为什么 == 不起作用?
我正在学习 Java,只是想出了一个关于该语言的微妙事实:如果我声明两个具有相同元素的整数数组并使用 ==
比较它们,结果是 false代码>.为什么会这样?比较不应该评估为
true
吗?
I'm learning Java and just came up with this subtle fact about the language: if I declare two integer Arrays with the same elements and compare them using ==
the result is false
. Why does this happen? Should not the comparison evaluate to true
?
public class Why {
public static void main(String[] args) {
int[] a = {1, 2, 3};
int[] b = {1, 2, 3};
System.out.println(a == b);
}
}
提前致谢!
推荐答案
使用Arrays.equals(arr1, arr2) 方法.
Use Arrays.equals(arr1, arr2) method.
==
运算符 只是检查两个引用是否指向同一个对象.
The ==
operator just checks if two references point to the same object.
测试:
int[] a = {1, 2, 3};
int[] b = a;
System.out.println(a == b); // returns true as b and a refer to the same array
int[] a = {1, 2, 3};
int[] b = {1, 2, 3};
System.out.println(Arrays.equals(a, b)); //returns true as a and b are meaningfully equal
相关文章