relational-operators

问题 Can someone explain what exactly the LeftFirst Boolean Flag is in Abstract Relational Comparison Algorithm in ECMAScript ? I know that there is only one operator < handling all other relational operators like > , >= , <= as mentioned in the ECMAScript specification in Abstract Relational Comparison using the LeftFirst Boolean Flag for, and example: when we write and run an operation like 10 > 5 the LeftFirst Boolean Flag becomes false , and the left operand 10 is moved to the right side where

问题 I'm doing an exercise of a book called programming in C language, trying to solve exercise 7.9 and so my code works perfectly until I add a conditional statement for the function to only accept variables greater than 0 I have tried changing it in many ways but nothing seems to work // Program to find the least common multiple #include <stdio.h> int main(void) { int lcm(int u, int v); printf("the least common multiple of 15 and 30 is: %i\n", lcm(15, 30)); return 0; } // Least common multiple

问题 i = 0; if(0 <= i <= 0) this returns false. I don't understand this at all. Watch window I also tried making the statement read (0 <= i && i <= 0) when I test them individually 0 <= i returns false while i <= 0 returns true. they both should be true. I'm not sure if this is a precision thing but I wouldn't think so since I'm hard coding the values in. Please help me understand this fundamental problem. If it helps I am trying to evaluate if a point is on a line by getting the intersection

问题 So I have a fairly complex function: template <typename T> void foo(const int param1, const int param2, int& out_param) Given int bar , const int arg1 , and const int arg2 the function will be called with either: foo<plus<int>>(arg1, arg2, bar) or foo<minus<int>>(arg1, arg2, bar) Internally the function is rather complex but I am doing different relational operators based on the type of functor that was passed as a template parameter. In the case of plus I need to do: arg1 > arg2 bar > 0 bar

问题 I\'m reading a book where the author says that if( a < 901 ) is faster than if( a <= 900 ) . Not exactly as in this simple example, but there are slight performance changes on loop complex code. I suppose this has to do something with generated machine code in case it\'s even true. 回答1: No, it will not be faster on most architectures. You didn't specify, but on x86, all of the integral comparisons will be typically implemented in two machine instructions: A test or cmp instruction, which sets