Relational operator in C while using real variables

Question

Why the output is not as expected?

#include <stdio.h>
void main(){
    float a,b,c;
    b=0.7;
    if( b<0.7 )
        printf(" It should NOT be here");
    else
        printf("It Should be here");
}

Answer 1

Floating point numbers

• have limited accuracy
• some value doesn't exist. 0.7 is such value. On my platform is 0.699999988. Reason: we write numbers as decimal, but internal are realised as binary. Many longer materials exist https://en.wikipedia.org/wiki/Floating-point_arithmetic#Representable_numbers.2C_conversion_and_rounding

So behaviour You are surprised

Answer 2

0.7 is double value. Try 0.7f in code. It should work.

Answer 3

Please Try the below Code, it works!!!:

Code

 #include <stdio.h>

    int  main(void)
    {

    float a,b,c,temp;
    temp=0.7;
    b=0.7;

    if( b<temp )
        printf(" It should NOT be here");
    else
        printf("It Should be here");


    }