1.5 - logical operation

Catalog

One 、 Logical operations

Two 、 To assist in understanding

3、 ... and ： Examination site ： Of logical operations

---

One 、 Logical operations

1. or ： One is true is true ;
2. And ： If one is false, it is false ;
3. Exclusive or ： True or false , All are false ; One true and one false is true ;
4. Same as or ： If it's all true, it's true , All false is true ; One true and one false is false ;
5. Not ： It is true or false ; If it is false, it is true ;

Two 、 To assist in understanding

1. 0 Said the false ,1 Said really ;

Be careful ：

Every logical operation has many symbols , Applicable to different environments ; for example || Applicable in code , Others can be used in algebraic operations ;

3、 ... and ： Examination site ： Of logical operations

1. From the title, we can see ,00、11 It is an effective expression of numerical symbols ; That is to say When the sign bits of both numbers are 00, or All are 11 when , their The result of logical operation is true （0）;
2. 01、10 Is an invalid representation of a numeric symbol ; That is, when the sign bits of two numeric values All are 01, perhaps All are 10 when , their The result of logical operation is false （1）;
3. So we can infer from this , Need to carry out Exclusive or Logical operations , In order to meet the requirements of the question, two numbers with the same symbol are added , The operation result overflows , It's fake （1）;

Be careful ：

When doing the problem of logical operation , In an abnormal situation , Overflow in the above question , Then his result is false , That is to say 1;