Programming

Question

#include<stdio.h>

int main()

{ Float x=0.5;

if(x==0.5)

Printf("if");

else if(x==0.5f)

Printf("else if");

}

Explain the code line by line .

Comments

is it 

if else if

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@A_i_$_h why not if?

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Compile it the output is "if"also explain it

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It will be showing error on "float x = 0.5;" as we have to explicitly tell compiler that we are assigning float value like "float x = 0.5f" otherwise it is considered as double. Well, it is compiler dependent whether they accept "float x = 0.5;" or not or including 'f' is compulsory for floating numbers.

If accepted the answer will be "if" => As for .5 we have proper binary representation. That's why condition stands true.

Much better explanation is given on the below link.

https://discuss.codechef.com/questions/48339/how-the-precision-for-floating-point-numbers-01-and-05-varies-in-c
Hope this helps.

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I think this question is related to the concept of precision .

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For more information about this question see comparison of a float with a value in c geeks for geeks and also explain

Thanks

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not clear.... a little more elaborate @harish kumar 2

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@A_i_$_h

Updated the previous comment. It was incorrect.

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it maens 0.5 and above is valid

it will print "if"

otherwise no right?

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int main(void) {
    float x = 0.4;
    if(x == 0.4)
    printf("1");
    else if(x == 0.4f)
    printf("2");
    return 0;
}

Out put : 2

And for
int main(void) {
    float x = 0.5;
    if(x == 0.5)
    printf("1");
    else if(x == 0.5f)
    printf("2");
    return 0;
}

Output : 1

That means if the number gets properly converted to binary then normal assignment(x == 0.5) will hold true otherwise have to give explicitly(x == 0.5f).

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how to check if its properly converting to binary

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It's compiler dependent.

#include<stdio.h>

int main()

{
    float x=0.55;
    if(x==0.55)
        printf("if");
    else if(x==0.55f)
        printf("else if");
    return 0;
}

This will print "else if"

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https://stackoverflow.com/questions/3954498/how-to-convert-float-number-to-binary

From here you can get the actual thing.

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@Tushin Dutta

.55 is actually not getting properly converted to binary number that's why it will always print "else if".

You can check from the link below whether a floating number will be converted into binary or not.

https://stackoverflow.com/questions/3954498/how-to-convert-float-number-to-binary

Answer 1

The answer should be else if becAuse decimal numbers are by default double so 0.5 is considered as double well the initialization should be as float x = 0.5f though, But it won't give any error but comparison of x with 0.5 will return false and else if will be printed.

yea its true as its compiler dependent.