scientific-notation-c

Scientific Notation in C

In this c program, we will learn how to print float or double value in exponential (scientific) format in c programming language?

Which format specifier specifies exponential format?

%e can be used to print value in exponential format of float or double value.

Let’s consider the following example - in this example there is a float type variable value and which is assigned by 123456.456 and value of variable value is printing using %f and %e format specifiers.

C program - Print value in Exponential Format

/*C program to print value in exponential (scientific) format */

#include <stdio.h>
int main()
{
 float value=123456.456f;
 
 printf("value: %f (using %%f format specifier)\n",value);
 printf("value: %e (using %%e format specifier)\n",value);
 
 return 0;
}

    value: 123456.453125 (using %f format specifier)
    value: 1.234565e+05 (using %e format specifier)

How to represent scientific notation in C

How do I represent extremely large or small numbers in C with a certain amount of significant figures. For example, if I want to do calculations on 1.54334E-34, how could I do this. Also, is this applicable to C language code?

#include <stdio.h>

int main()

{

    float var = 1.54334E-34;

    double var2 = 1.54334E-34;

    printf("\n normal:%f\n sci:%e \n or \n sci:%E   \n",var,var,var);

    printf("\n normal:%f\n sci:%e \n or \n sci:%E   \n",var2,var2* 1.0E3 ,var2 * 1.0e3);

    return 0;

}

Output:

normal:0.000000                                                                                                                                 
sci:1.543340e-34     
or
sci:1.543340E-34


normal:0.000000                                                                                                                                   
sci:1.543340e-31         
or
sci:1.543340E-31

#include <stdio.h>
 
int main()
{
    float lightyear = 5.878E12;
    float jupiter = 483400000;
    float distance;
 
    distance = jupiter/lightyear;
 
    printf("Jupiter is %E light years from the sun.\n",distance);
 
    return(0);
}

Jupiter is 8.223886E-005 light years from the sun.