Byte a = 123;
a++;
System.out.println(a);// 124
/*
* 上面的结论是: a++的时候首先是 创建一个Byte对象124,然后将a引用指向这个Byte 124对象,这个解释有问题吗?
*/
Byte b = 126;
b = b++;
System.out.println(b);// 126
/*
* 根据第一段代码的执行结果;
* b=b++,的执行操作是首相将b引用赋值给b引用,所以没有改变,然后将b引用所指向的对象自增(这个实现的过程是创建一个对象值为127,
* 然后让b引用指向这个127),如果这样理解,结果不应该是127吗
*/
求解,谢谢
大家讲道理2017-04-18 10:58:08
b = b++: If you know C++, you can refer to the auto-increment implementation of ++, and you should be able to understand why it is 126
Byte operator++(Byte) {
Byte temp = *this;
this->value = this->value + 1;
return temp;
}
can be understood as b is equal to temp before the operation is incremented
PHP中文网2017-04-18 10:58:08
++, --Be sure to write it separately, otherwise you will cause trouble for yourself.
For questions like i=i+++++i
, I can only despise...
巴扎黑2017-04-18 10:58:08
Java stack frame contains local variable table and operand stack. The ++ auto-increment operation is direct operation on the value in the local variable table. When i=i++, first push the i in the local variable table into the operand stack. Then add 1 to i in the local variable table to become 127, and then write i (126) in the operand stack back to i in the local variable table, covering the 127 data and changing it to 126. The order of ++i is different. It first increments i in the local variable table and then adds it to the operand stack.