下列:
class ArrayCompare
{
public static void main (String[] args)
{
int []arr1 = {1, 2, 3, 4, 5};
int []arr2 = {1, 2, 3, 4, 5};
System.out.println("arr1 == arr2 is " + (arr1 == arr2));
}
}
Run Code Online (Sandbox Code Playgroud)
返回 arr1 == arr2 is false
为什么是这样?为什么arr1 Equals to arr2是false.
这不是真的吗?
对于一个简单的Java程序,我希望通过递增2或3或4来使程序从10计数到1,我将如何更改此代码?
public class ExampleFor {
public static void main(String[] args) {
//
for(int i = 10; i > 0; i--){
System.out.println("i = " + i);
}
}
}
Run Code Online (Sandbox Code Playgroud) 我在测试中遇到过这个问题:
class Hello {
public static void main(String[] args){
String hello = "Hello", lo = "lo";
System.out.println(hello == ("Hel" + "lo"));
System.out.println(hello == ("Hel" + lo));
System.out.println(hello == ("Hel" + lo).intern());
}
}
Run Code Online (Sandbox Code Playgroud)
输出是:
true
false
true
Run Code Online (Sandbox Code Playgroud)
为什么是第二个输出false?