comparison-operators

Yesterday I stumbled over this when I modified PHP code written by someone else. I was baffled that a simple comparison ( if ($var ==! " ") ) didn't work as expected. After some testing I realized that whoever wrote that code used ==! instead of !== as comparison operator. I've never seen ==! in any language so I wondered how the hell this code could even work and did some testing: <?php echo "int\n"; echo "1 !== 0: "; var_dump(1 !== 0); echo "1 !== 1: "; var_dump(1 !== 1); echo "1 ==! 0: "; var_dump(1 ==! 0); echo "1 ==! 1: "; var_dump(1 ==! 1); echo "bool\n"; echo "true !== false: "; var

Can anyone explain this to me? Did I do something wrong? When I run the program it doesn't show me the right answer. ex : when I type weight = 50 kg and height = 130 cm the answer should be "Your BMI is 29.58. You are overweight2.You will have a chance to cause high blood pressure and diabetes need to control diet. And fitness." but the answer that shows is "Your BMI is 29.58. You are normal......" #include<stdio.h> #include<conio.h> int main() { float weight, height, bmi; printf("\nWelcome to program"); printf("\nPlease enter your weight(kg) :"); scanf("%f", &weight); printf("\nPlease enter

I am new to JAVA programming. I have read it in my book String a="Hello"; String b="Hello"; System.out.println(a==b); This should return false as a & b refer to different instances of String objects. Bcoz the assignments operator compares the instances of objects but Still I am getting a true . I am using Eclipse IDE. Example in book goes as this: String s = "s"; String sToo = "s"; System.out.println(a == b); System.out.println(s == sToo); That bit of code prints “false” for s == sToo. That's because s and sToo are references to different instances of the String object. So, even though they

Can I do this in C++? if (4<5<6) cout<<"valid"<<endl; i.e a double comparison? Since I know that I can bool a; a = 1+2<3+4<5>6;//etc Yes, you can do it, but it won't be what you expect. It's parsed as if ( (4<5) < 6 ) which yields if ( 1 < 6 ) because 4<5 evaluates to true which is promoted to 1 , which yields, obviously, true. You'll need if ( (4<5) && (5<6) ) Also, yes, you can do a = 1+2<3+4<5>6; but that as well is parsed as a = ((1+2)<((3+4)<5))>6; which will evaluate to false since (1+2)<((3+4)<5) yields a boolean, which is always smaller than 6. It compiles but won't do what you expect

I want to get a number input by the user via input() and compare it with a specific value, i.e., 3 . However, I have the impression my if statement doesn't work. The comparison is always False . Start = input() if Start == 3: print ("successful") Python 3 input function returns string. Try like this start = input("-->: ") if start == "3": print("successful") moooeeeep Some things you could do on your own to get to the root of the problem: Ways to get to know the type of the object: print(type(start)) # prints <class 'str'> print(repr(start)) # prints '3' Unlike Python 2.x, the function input()

I've been thus far unable to find this information in the official PHP docs, or on this site. So, that may mean I'm searching under the wrong terms, or it is not supported. What am I looking for? I'll describe it... Let's say I have the following comparisons in PHP: if (($a == $b) && ($b == $c)) doSomething(); else doSomethingElse(); if (($d < $e) && ($e < $f)) doSomething(); else doSomethingElse(); Does PHP have some kind of syntax to chain the comparisons together without the explicit AND-ing of two different comparisons? For example, is something like this possible: if ($a == $b == $c)

I wrote a bash script that performs a curl call only during business hours. For some reason, the hourly comparison fails when I add an "-a" operator (and for some reason my bash does not recognize "&&"). Though the script is much larger, here is the relevant piece: HOUR=`date +%k` if [ $HOUR > 7 -a $HOUR < 17 ]; then //do sync fi The script gives me the error: ./tracksync: (last line): Cannot open (line number): No such file However, this comparison does not fail: if [ $DAY != "SUNDAY" -a $HOUR > 7 ]; then //do sync fi Is my syntax wrong or is this a problem with my bash? You cannot use < and