问题
Table true/false for C Language
I have heard of a table true false for C Language for and && or || is kind of the mathematics one for which they say if true+true=true and false+true=false
I'm just kind of confuse on this and I tried to do the research but couldn't find any of the table
I just wish to have this table for my notes since I will do more in C language
if someone could bring me to the site or resources where they explain about this more
I've edited my original question to make it a note for my own study. Thanks @thiton for the great references and the rest for an awesome answer/resources.
Logical AND (&&)
false && false: false
false && true: false
true && false: false
true && true: true
Logical OR (||)
false || false: false
false || true: true
true || false: true
true || true: true
Logical NOT (!)
!false: true
!true: false
回答1:
You probably mean a truth table for the boolean operators, which displays the result of the usual boolean operations (&&, ||). This table is not language-specific, but can be found e.g. here.
回答2:
You're thinking of Boolean algebra.
回答3:
Truth values can be described using a Boolean algebra. The article also contains tables for and
and or
. This should help you to get started or to get even more confused.
回答4:
I think You ask for Boolean algebra which describes the output of various operations performed on boolean variables. Just look at the article on Wikipedia.
回答5:
I`d like to add to the already good answers:
The symbols '+', '*' and '-' are sometimes used as shorthand in some older textbooks for OR,∨ and AND,∧ and NOT,¬ logical operators in Bool`s algebra. In C/C++ of course we use "and","&&" and "or","||" and "not","!".
Watch out: "true + true" evaluates to 2 in C/C++ via internal representation of true and false as 1 and 0, and the implicit cast to int!
int main ()
{
std::cout << "true - true = " << true - true << std::endl;
// This can be used as signum function:
// "(x > 0) - (x < 0)" evaluates to +1 or -1 for numbers.
std::cout << "true - false = " << true - false << std::endl;
std::cout << "false - true = " << false - true << std::endl;
std::cout << "false - false = " << false - false << std::endl << std::endl;
std::cout << "true + true = " << true + true << std::endl;
std::cout << "true + false = " << true + false << std::endl;
std::cout << "false + true = " << false + true << std::endl;
std::cout << "false + false = " << false + false << std::endl << std::endl;
std::cout << "true * true = " << true * true << std::endl;
std::cout << "true * false = " << true * false << std::endl;
std::cout << "false * true = " << false * true << std::endl;
std::cout << "false * false = " << false * false << std::endl << std::endl;
std::cout << "true / true = " << true / true << std::endl;
// std::cout << true / false << std::endl; ///-Wdiv-by-zero
std::cout << "false / true = " << false / true << std::endl << std::endl;
// std::cout << false / false << std::endl << std::endl; ///-Wdiv-by-zero
std::cout << "(true || true) = " << (true || true) << std::endl;
std::cout << "(true || false) = " << (true || false) << std::endl;
std::cout << "(false || true) = " << (false || true) << std::endl;
std::cout << "(false || false) = " << (false || false) << std::endl << std::endl;
std::cout << "(true && true) = " << (true && true) << std::endl;
std::cout << "(true && false) = " << (true && false) << std::endl;
std::cout << "(false && true) = " << (false && true) << std::endl;
std::cout << "(false && false) = " << (false && false) << std::endl << std::endl;
}
yields :
true - true = 0
true - false = 1
false - true = -1
false - false = 0
true + true = 2
true + false = 1
false + true = 1
false + false = 0
true * true = 1
true * false = 0
false * true = 0
false * false = 0
true / true = 1
false / true = 0
(true || true) = 1
(true || false) = 1
(false || true) = 1
(false || false) = 0
(true && true) = 1
(true && false) = 0
(false && true) = 0
(false && false) = 0
来源:https://stackoverflow.com/questions/7583853/true-and-false-for-logic-and-logic-table