+ 6
Boolean logic and loops
When does Boolean logic apply to an if loop? I'm certain I've seen it applied before, but in the following code it's not applicable: #include <iostream> using namespace std; int x = 1; int y = 1; int main() { if (x + y == 1) {cout << "It worked"<<endl;} else cout << "It didn't work" << endl; return 0; }
13 Antworten
+ 23
The code works perfectly.
1 + 1 is 2 and 2 is clearly not 1. The code outputs "It didn't work".
+ 26
First of all, if statement isn't a loop - it's a conditional statement like the switch.
Whatever you put in an if statement, boils down to a boolean "true/1" or "false/0" value.
For example:
// Example program
#include <iostream>
#include <cmath>
using namespace std;
int main() {
int a = -1;
int b = 128;
int c = 0;
float d = 1.45f / 98.0f;
double e = (2.71 + 3.14) * 30.0;
double f = sin(e);
char g = 'H';
long long h = 12345678912345;
if (a) cout << "a Done.\n";
if (b) cout << "b Done.\n";
if (c) cout << "c Done.\n";
if (d) cout << "d Done.\n";
if (e) cout << "e Done.\n";
if (f) cout << "f Done.\n";
if (g) cout << "g Done.\n";
if (h) cout << "h Done.\n";
}
https://code.sololearn.com/chAYAQ13fHDD
+ 20
So give up vote to all friend who clarified the point for you, my friend.
+ 20
Thanks dear Hatsy for useful tip. really worth to put it in my tutorial series.
@~)~~~~
+ 14
Indeed, anything which is not 0 and not false is evaluated to true in C++, but in
if (1 + 1 == 1)
All the values are taken as integer values. Hence LHS and RHS value does not tally, and the statement is evaluated as false. Try doing
if (bool(1 + 1) == true)
// or
if (bool(1 + 1) == 1)
These will yield different results.
+ 12
Also, the 'if' keyword is associated with conditional statements. There is no such thing as 'if loops'.
+ 6
if (x+y==1) comes the boolean
+ 5
I think boolean logic will not work here so here, 1+1==2 and not 1 as both the 1's are taken as decimal numbers, not binary numbers. So if statement doesn't executed and it shows "It didn't work".
+ 5
Okay, I got confused because if I write something like
"int i =5;
if (i == 5)" this evaluates to
if (true)."
I thought that in this case as long as the number was anything other than 0 the code would consider the statement true, as in boolean logic, but this is not the case. It checks the condition truthfully, then the answer becomes 1 (true) or 0 (false).
Thanks.
+ 4
First up, if statement is not a loop...
It will execute when the condition is true, and not when it is false.
if is a conditional statement.
+ 2
True. If-statements
+ 1
true if statement..
0
Boolean logic