CODEWITHSUNDEEP
c++if-statement
Johnston
Johnston

Reputation: 2883

If statement not seeming to check other && in statement

I have an if statement that looks as follows:

int count=0;
string Check;

if ((count==4 && Check!="-s")||(count==4 && Check!="-S"))

If count equals 4 and Check equals "-s" or "-S" it still enters this if statement because of the count == 4. It totally seems to ignore the second part. Is there something I'm doing wrong?

Upvotes: 1

Views: 165

Answers (7)

Matteo Melani
Matteo Melani

Reputation: 2726

You want to enter the if body if and only if Check is != from either -s or -S and count is = 4 right?

if ( (Check!="-s" && Check!="-S") && count==4 )

should work.

or

if ( Check.tolower() !="-s" && count==4 )

should work.

(Do not remember the name of the function to lowercase a string, you have got to look it up)

Hope this help.

Upvotes: 1

Ravi
Ravi

Reputation: 3766

Might be more clear to use:

if (count==4 && Check!="-s" && Check!="-S")

Upvotes: 2

vrxacs
vrxacs

Reputation: 173

The right statement is:

if(count==4 && (Check != "-s" || Check!="-S"))

The statement that you wrote is true if you have count = 4 and Check = "-S" because then the first part of the OR is true.

Upvotes: 2

Xeo
Xeo

Reputation: 131837

Well, if Check is "-S", then it will not even check the second pair of conditions, because you check with ||. The same holds true for the opposite case. If one is false, the other is true. Replace that with a &&.

int count = 4;
string Check = "-S";

if( (count == 4 && // count is 4, alright.
     Check != "-s") || // Check is "-S", alright I'm done thanks to || (OR)
    (count == 4 &&
     Check != "-S") )
{
  // ...
}

int count = 4;
string Check = "-s";

if( (count == 4 && // count is 4, alright.
     Check != "-s") || // Check is "-S", time to check the other condition pair...
    (count == 4 && // count is 4, alright.
     Check != "-S") ) // Check is "-s", which is different from "-S", perfect.
{
  // ...
}

Now the corrected version:

int count = 4;
string Check = "-S";

if( (count == 4 && // count is 4, alright.
     Check != "-s") && // Check is "-S", different from "-s", now on to the other condition!
    (count == 4 && // count is 4, alright.
     Check != "-S") ) // Check is "-S"... oh dang! No executed code for you.
{
  // ...
}

Upvotes: 2

ayckoster
ayckoster

Reputation: 6847

You should use !strcmp(Check, "-s") and !strcmp(Check, "-S") instead of !=.

If you use == you compare the pointers and that is no what you want. The pointers will always be different thus your second argument will always be true.

Upvotes: 1

borrible
borrible

Reputation: 17376

It's always going to be the case that either Check!="-s" or Check!="-S". Hence, your if statement is equivalent to if (count==4).

Upvotes: 4

FishBasketGordo
FishBasketGordo

Reputation: 23142

If count == 4 and Check == "-s", then the expression to the right of the || is true. If count == 4 and Check == "-S", then the expression to the left of the || is true. So you have true or true which is true. Thus, your if-block is executed.

Upvotes: 2

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