Q: What will be the output of the program? #include int main() { float a=0.7; if(a < 0.7f) printf("C\n"); else printf("C++\n"); return 0; }

if(a int main() { float a=0.7; printf("%.10f %.10f\n",0.7f, a); return 0; } Output: 0.6999999881 0.6999999881

Question 1

What will you do to treat the constant 3.14 as a long double?

Accepted Answer

Given 3.14 is a double constant. To specify 3.14 as long double, we have to add L to the 3.14. (i.e 3.14L)

Question 2

What will you do to treat the constant 3.14 as a float?

Accepted Answer

Given 3.14 is a double constant. To specify 3.14 as float, we have to add f to the 3.14. (i.e 3.14f)

Question 3

We want to round off x, a float, to an int value, The correct way to do is

Accepted Answer

Rounding off a value means replacing it by a nearest value that is approximately equal or smaller or greater to the given number. y = (int)(x + 0.5); here x is any float value. To roundoff, we have to typecast the value of x by using (int) Example: 
#include <stdio.h>

int main ()
{
  float x = 3.6;
  int y = (int)(x + 0.5);
  printf ("Result = %d
", y );
  return 0;
}
 Output: Result = 4.

Question 4

Which of the following statement obtains the remainder on dividing 5.5 by 1.3?

Accepted Answer

fmod(x,y) - Calculates x modulo y, the remainder of x/y. This function is the same as the modulus operator. But fmod() performs floating point divisions. Example: #include #include int main () { printf ("fmod of 5.5 by 1.3 is %lf ", fmod (5.5, 1.3) ); return 0; } Output: fmod of 5.5 by 1.3 is 0.300000

Question 5

Which of the following range is a valid long double (Turbo C in 16 bit DOS OS)?

Accepted Answer

The range of long double is 3.4E-4932 to 1.1E+4932

Question 6

Which statement will you add in the following program to work it correctly? #include<stdio.h>
int main()
{
    printf("%f
", log(36.0));
    return 0;
}

Accepted Answer

math.h is a header file in the standard library of C programming language designed for basic mathematical operations. Declaration syntax: double log(double);

Question 7

What are the different types of real data type in C?

Accepted Answer

The floating point data types are called real data types. Hence float, double, and long double are real data types.

Question 8

What will be the output of the program? #include<stdio.h>
int main()
{
    float d=2.25;
    printf("%e,", d);
    printf("%f,", d);
    printf("%g,", d);
    printf("%lf", d);
    return 0;
}

Accepted Answer

printf("%e,", d); Here '%e' specifies the "Scientific Notation" format. So, it prints the 2.25 as 2.250000e+000. printf("%f,", d); Here '%f' specifies the "Decimal Floating Point" format. So, it prints the 2.25 as 2.250000. printf("%g,", d); Here '%g' "Use the shorter of %e or %f". So, it prints the 2.25 as 2.25. printf("%lf,", d); Here '%lf' specifies the "Long Double" format. So, it prints the 2.25 as 2.250000.

Question 9

What will be the output of the program? #include<stdio.h>
int main()
{
    float *p;
    printf("%d
", sizeof(p));
    return 0;
}

Accepted Answer

sizeof(x) returns the size of x in bytes. float *p is a pointer to a float. In 16 bit compiler, the pointer size is always 2 bytes. In 32 bit compiler, the pointer size is always 4 bytes.

Question 10

What will be the output of the program? #include<stdio.h>
int main()
{
    float a=0.7;
    if(a < 0.7f)
        printf("C
");
    else
        printf("C++
");
    return 0;
}

Accepted Answer

if(a < 0.7f) here a is a float variable and 0.7f is a float constant. The float variable a is not less than 0.7f float constant. But both are equal. Hence the if condition is failed and it goes to else it prints 'C++' Example: #include<stdio.h>
int main()
{
    float a=0.7;
    printf("%.10f %.10f
",0.7f, a);
    return 0;
}
 Output: 0.6999999881 0.6999999881

Question 11

What will be the output of the program? #include<stdio.h>
int main()
{
    float a=0.7;
    if(a < 0.7)
        printf("C
");
    else
        printf("C++
");
    return 0;
}

Accepted Answer

if(a < 0.7) here a is a float variable and 0.7 is a double constant. The float variable a is less than double constant 0.7. Hence the if condition is satisfied and it prints 'C' Example: #include<stdio.h>
int main()
{
    float a=0.7;
    printf("%.10f %.10f
",0.7, a);
    return 0;
}
 Output: 0.7000000000 0.6999999881

Question 12

What will be the output of the program? #include #include int main() { printf("%f ", sqrt(36.0)); return 0; }

Accepted Answer

printf("%f
", sqrt(36.0)); It prints the square root of 36 in the float format(i.e 6.000000). Declaration Syntax: double sqrt(double x) calculates and return the positive square root of the given number.

Question 13

What will be the output of the program? #include #include int main() { printf("%d, %d, %d ", sizeof(3.14f), sizeof(3.14), sizeof(3.14l)); return 0; }

Accepted Answer

sizeof(3.14f) here '3.14f' specifies the float data type. Hence size of float is 4 bytes. sizeof(3.14) here '3.14' specifies the double data type. Hence size of float is 8 bytes. sizeof(3.14l) here '3.14l' specifies the long double data type. Hence size of float is 10 bytes. Note: If you run the above program in Linux platform (GCC Compiler) it will give 4, 8, 12 as output. If you run in Windows platform (TurboC Compiler) it will give 4, 8, 10 as output. Because, C is a machine dependent language.

Question 14

What will be the output of the program? #include #include int main() { float n=1.54; printf("%f, %f ", ceil(n), floor(n)); return 0; }

Accepted Answer

ceil(x) round up the given value. It finds the smallest integer not < x. floor(x) round down the given value. It finds the smallest integer not > x. printf("%f, %f
", ceil(n), floor(n)); In this line ceil(1.54) round up the 1.54 to 2 and floor(1.54) round down the 1.54 to 1. In the printf("%f, %f
", ceil(n), floor(n)); statement, the format specifier "%f %f" tells output to be float value. Hence it prints 2.000000 and 1.000000.

Question 15

What will be the output of the program? #include<stdio.h>
int main()
{
    float f=43.20;
    printf("%e, ", f);
    printf("%f, ", f);
    printf("%g", f);
    return 0;
}

Accepted Answer

printf("%e, ", f); Here '%e' specifies the "Scientific Notation" format. So, it prints the 43.20 as 4.320000e+01. printf("%f, ", f); Here '%f' specifies the "Decimal Floating Point" format. So, it prints the 43.20 as 43.200001. printf("%g, ", f); Here '%g' "Use the shorter of %e or %f". So, it prints the 43.20 as 43.2.

Question 16

What will be the output of the program? #include<stdio.h>
int main()
{
    float fval=7.29;
    printf("%d
", (int)fval);
    return 0;
}

Accepted Answer

printf("%d
", (int)fval); It prints '7'. because, we typecast the (int)fval in to integer. It converts the float value to the nearest integer value.

Floating Point Issues Questions