Integer i3 = Integer.valueOf(129); Integer i4 = Integer.valueOf(129); System.out.println(i3==i4);

The output of this code will be false.

This is because the Integer class caches frequently used values between -128 and 127, so when we use Integer.valueOf() to create an Integer object with a value within this range, it will return the same object instance for the same value. However, in this case, the value 129 is outside of this range, so two separate object instances will be created and compared using ==, which checks if they are the same object in memory. Therefore, the output will be false.

相关问题

Integer i3 = Integer.valueOf(5); Integer i4 = Integer.valueOf(5); System.out.println(i3==i4);

The output of this code will be "true".

Explanation:
When we use the Integer.valueOf() method to create Integer objects with values between -128 and 127, the JVM caches these objects and returns the same object for subsequent calls to the method with the same argument.

In this case, both i3 and i4 have the value 5, which falls within the cached range. Therefore, both Integer objects are the same object in memory, and the comparison using the == operator will return true.

得到一下代码的值并说明原因：Integer i8=Integer.valueOf("11",16); System.out.println("i8="+i8); int i9= Integer.valueOf("15"); System.out.println("i9="+i9); int i10=Integer.parseInt("15",16); System.out.println("i10="+i10);

输出结果为：

i8=17
i9=15
i10=21

原因如下：

- `Integer.valueOf("11",16)`：将字符串"11"解释为十六进制数，转换为对应的整数值并赋给变量i8，因为十六进制的"11"在十进制中表示的是17。
- `Integer.valueOf("15")`：将字符串"15"解释为十进制数，转换为对应的整数值并赋给变量i9。
- `Integer.parseInt("15",16)`：将字符串"15"解释为十六进制数，转换为对应的整数值并赋给变量i10，因为十六进制的"15"在十进制中表示的是21。注意，此处使用的是parseInt方法而非valueOf方法。parseInt方法直接将字符串解析为整数，而valueOf方法可以解析不同进制的字符串。