here is my code :
string function1( string input)
{
string output;
int i=0;
if (input.at(i)!='A' || input.at(i)!='a'|| input.at(i)!='E' || input.at(i)!='e' || input.at(i)!='I' || input.at(i)!='i' || input.at(i)!='O'||input.at(i)!='o' || input.at(i)!='U' || input.at(i)!='u')
{
char x=input[i];
input.erase(input.begin()+i);
output=input+x;
}
else
{
output=input+"yay";
}
return output;
}
but its not doing what i want it to do.. can't figure out where its going wrong...
can any1 help?
Basically the issue is that its never going in to the else statement..
if i pass in BJ it should return BJYAY right..
but its giving me JB
Thanks!
Change the || operators of the if statement to &&. The statement you have written is always true. What you want is that the first character is not a vowel, i.e. it does not match 'A' AND it does not match 'E', etc.
Changing the != to == will give you the result requested.
Related
bool x = someFuncThatReturnsTrueorFalse();
if (!x && (str1.length() != str2.length()) {
// do nothing
} else {
// do something
}
How would I rearrange the code above to eliminate the else statement?
I need to do nothing if bool = false and str1 and str2 have different lengths. Otherwise, I need to do something (e.g. function call).
For the life of me, I can't think of any way to change this. Let me know if you need further details.
The simplest way is putting !() around the condition.
bool x = someFuncThatReturnsTrueorFalse();
if (!(!x && (str1.length() != str2.length())) {
// do something
}
Another way is using De Morgan's laws: !(A && B) is equivalent to !A || !B.
bool x = someFuncThatReturnsTrueorFalse();
if (x || (str1.length() == str2.length()) {
// do something
}
There is nothing wrong leaving as is. The code will still compile
So I know that generally speaking, I should prefer an else-if over and if if. But what if the two conditions aren't related? For example, these would be considered "related" conditionals:
if (line[a] == '{'){
openCurly = true;
}
else if (line[a] == '}'){
closeCurly = false;
}
Notice how the two conditionals in the if-statements are related in a way such that when one is true, the other must be false. This is because line[a] can either be { or } but not both.
Here is another example:
if (line[a] == '{')
{
openCurly = true;
}
else if ((line[a] == ';' && !openCurly) || (line[a] == '}' && openCurly))
{
DoSomething(line);
line = "";
}
The second condition will never evaluate to true if the first condition if true, so it makes sense to have an else-if. However, those two conditionals look vastly different.
So, should I prefer something like this?
if (line[a] == '{')
{
openCurly = true;
}
if ((line[a] == ';' && !openCurly) || (line[a] == '}' && openCurly))
{
DoSomething(line);
line = "";
}
You should use an else-if statement. This is because an if-else construct only checks the second statement if the first one doesn't evaluate to true.
In the example you give,
if (line[a] == '{')
{
openCurly = true;
}
else if ((line[a] == ';' && !openCurly) || (line[a] == '}' && openCurly))
{
DoSomething(line);
line = "";
}
replacing the else if with an if statement would result in the second condition being checked even if the first one is true, which is completely pointless and would also lose you some time.
In the future, make decisions to use else-if statements based on whether the conditions are mutually exclusive or not.
You could do something like this:
#include <stdint.h>
#define COMBINATION(x, y) ((uint16_t(x) << 8) | (uint16_t(y) << 0))
...
switch (COMBINATION(line[a], openCurly))
{
case COMBINATION('{', false):
...
break;
case COMBINATION(';', false):
case COMBINATION('}', true):
...;
break;
}
}
Some may say it's a bit of an overkill, but I think that it may actually help splitting up the logical operation of your program into a set of distinct cases, thus make it easier to handle each case precisely as desired.
This question already has answers here:
What is a debugger and how can it help me diagnose problems?
(2 answers)
Closed 5 years ago.
Was making a small code for a text based game but i tried to do thinks a bit different than the tutorial sort of to test my understanding but i tried to get a function value to make a do while statement but it seems whether the statement false or true the code just keep looping infinitely im a beginner so pls if you have a time explain why the code is faulty and Thank you in Advance
The main function
int main() {
PrintIntroStart();
do {
PlayGame();
AskToPlayAgain();
} while (AskToPlayAgain() == true);
return 0;
}
the Bool Function
bool AskToPlayAgain(){
//Asking The Player Whether To Play Again Or Not
std::string PlayerResponse = "";
std::cout << "Do You Want To Play Again? (Yes/No)" << std::endl;
std::cin >> PlayerResponse;
if (PlayerResponse[0] == 'y' || 'Y')
return true;
else
return false;
}
Also, here you are asking twice to play again
do {
PlayGame();
AskToPlayAgain();
} while (AskToPlayAgain() == true);
this should be
do {
PlayGame();
} while (AskToPlayAgain() == true);
if (PlayerResponse[0] == 'y' || 'Y') this one should be
if (PlayerResponse[0] == 'y' || PlayerResponse[0] == 'Y')
Otherwise your if condition is always true, because 'Y' itself is non-zero.
And in fact you don't need this if statement, just
return PlayerResponse[0] == 'y' || PlayerResponse[0] == 'Y';
So first of all, you are only checking the outcome of the game every second play.
You should follow #ziza s answer and remove the function call inside the loop.
The second problem, that causes the infinite loop is your input check.
A bool value in c++ is not a single bit, but just anoter regular value that is evaluated as false if it is 0 and to true if it has any other value. In your case the first comparison will evauate to 1 if the player input is 'y' and the second part of the condition will be the value of the 'Y' character (which is not 0). So your condition will always be true like #liliscent stated.
I've written the code bits below. I have a constructor which takes five arguments. Unfortunately, the setGender method spits out a default 'M' for all instances of a class rather than setting the gender to the specified parameter. What am I doing incorrectly? Any advice would be greatly appreciated. Thank you.
DateProfile::DateProfile(char gdr,
char searchGdr, int romanceScale, int financeScale, string theName)
bool DateProfile::setGender(char gdr)
{
if (gdr != 'M' || gdr != 'F')
return false;
gender = gdr;
return true;
}
if (gdr != 'M' || gdr != 'F') is always true, irrespective of input. If you're passing 'M', the second part of the expression is true. If you're passing anything else, the first part of the expression becomes true.
What you meant to write is if (gdr != 'M' && gdr != 'F') instead.
Increasing the warning level of your compiler may have helped you spot the error. Most compilers will warn about expressions always evaluating to a single value, or at least about the unreachable code following it.
I'm having a problem regarding with if statement in C++ this statement is in do-while loop.
gotoxy(27,22);cout<<"Do you want to continue [Y]?";
sub=getche();
if(sub!='y' || sub!='Y')
{
gotoxy(27,24);cout<<"INVALID ANSWER!!";
gotoxy(27,26);cout<<"Closing Program....";
delay(3000);
exit(1);
}else
{
sub=ans;
}
}while(tolower(ans)=='y');
whenever I input y on the variable sub the code on if statement is still executing.. please someone tells me where is the error.. Thanks!
The boolean expression of (sub!='y' || sub!='Y') will always evaluate to true
This line:
if(sub!='y' || sub!='Y')
Needs to be this:
if ( (sub != 'y') && (sub != 'Y') )
Your code if(sub!='y' || sub!='Y') will be true ,no matter what you enter because eithersub!='y' or sub!='Y' will evaluate to true. Hence Use && instead of ||.