The Most Commonly Used Format Specifiers in C Format Specifiers Type of Output %s A string or sequence of character %lf double %Lf Long double %o %u Octal integer Short unsigned integer 7 more rows Jul 19, 2024

%g and %e in c | Code Ease (2024)

Answered on: Wednesday 24 January, 2024 / Duration: 14 min read

Programming Language: C , Popularity :7/10

Solution 1:

In C programming, the %g and %e format specifiers are used with the printf and sprintf functions to format floating-point numbers.

1. %g Format Specifier:
- %g is used to print a floating-point number in either %f or %e format, depending on the precision and the magnitude of the number.
- It automatically chooses between %f and %e to represent the number in a concise and readable form.
- It removes trailing zeros and uses exponential notation for very large or very small numbers.

c
 #include <stdio.h>
 int main() {
 double number = 12345.6789;
 printf("Using %%g: %g\n", number);
 return 0;
 }

Output:


 Using %g: 12345.7

2. %e Format Specifier:
- %e is used to print a floating-point number in scientific notation (exponential format).
- It represents the number as a coefficient and an exponent.
- The %e format specifier is useful for displaying very large or very small numbers.

c
 #include <stdio.h>
 int main() {
 double number = 0.000012345;
 printf("Using %%e: %e\n", number);
 return 0;
 }

Output:


 Using %e: 1.234500e-05

In both examples, the specified format specifiers are used within the printf function to display the floating-point numbers in the desired format. The outputs demonstrate how the numbers are represented using %g and %e respectively.

Solution 2:

The %g and %e specifiers in C are used to format floating-point numbers. The %g specifier prints the number in either decimal or exponential format, whichever is more compact. The %e specifier always prints the number in exponential format.

The following code shows how to use the %g and %e specifiers to format floating-point numbers:

c
#include <stdio.h>
int main() {
 float f1 = 1.23456789;
 double f2 = 1.23456789e10;
 printf("f1 = %g\n", f1); // prints 1.234568
 printf("f2 = %g\n", f2); // prints 1.234568e10
 printf("f1 = %e\n", f1); // prints 1.234568e+00
 printf("f2 = %e\n", f2); // prints 1.234568e+10
 return 0;
}

The output of this code is:


f1 = 1.234568
f2 = 1.234568e+10
f1 = 1.234568e+00
f2 = 1.234568e+10

The %g specifier is the default specifier for floating-point numbers, so you can also use it to format numbers without explicitly specifying the specifier.

The following code shows how to use the %g specifier to format floating-point numbers:

c
#include <stdio.h>
int main() {
 float f1 = 1.23456789;
 double f2 = 1.23456789e10;
 printf("f1 = %f\n", f1); // prints 1.234568
 printf("f2 = %f\n", f2); // prints 1.234568e10
 return 0;
}

The output of this code is the same as the output of the previous code.

The %g specifier can be used with a precision specifier to control the number of digits after the decimal point. The following code shows how to use the precision specifier with the %g specifier:

c
#include <stdio.h>
int main() {
 float f1 = 1.23456789;
 double f2 = 1.23456789e10;
 printf("f1 = %.3g\n", f1); // prints 1.235
 printf("f2 = %.3g\n", f2); // prints 1.23457e+10
 return 0;
}

The output of this code is:


f1 = 1.235
f2 = 1.23457e+10

The %e specifier always prints the number in exponential format. The exponent is always a positive number, even if the number is negative. The following code shows how to use the %e specifier to format floating-point numbers:

c
#include <stdio.h>
int main() {
 float f1 = 1.23456789;
 double f2 = 1.23456789e10;
 printf("f1 = %e\n", f1); // prints 1.234568e+00
 printf("f2 = %e\n", f2); // prints 1.234568e+10
 return 0;
}

The output of this code is:


f1 = 1.234568e+00
f2 = 1.234568e+10

The %e specifier can be used with a precision specifier to control the number of digits after the decimal point. The following code shows how to use the precision specifier with the %e specifier:

c
#include <

Solution 3:

In C programming language, %g and %e are format specifiers used with the printf() and scanf() functions for formatting and printing floating point numbers.

The %g format specifier is used to print a floating point number in either decimal or exponential notation, whichever is shorter. It automatically chooses the appropriate format based on the size of the number. If the number is less than 1e-4 or greater than 1e6, it will be printed in exponential notation. Otherwise, it will be printed in decimal notation.

Here's an example:

c
#include <stdio.h>
int main() {
 float num = 12345.678;
 printf("Percent g: %g\n", num);
 return 0;
}

Output:


Percent g: 12345.7

In this example, the number 12345.678 is printed in decimal notation because it is greater than 1e-4 and less than 1e6.

The %e format specifier is used to print a floating point number in exponential notation. It always prints the number with a decimal point and a single digit before the decimal point. The exponent is introduced by the letter e or E, followed by the exponent as a decimal number.

Here's an example:

c
#include <stdio.h>
int main() {
 float num = 0.000012345;
 printf("Percent e: %e\n", num);
 return 0;
}

Output:


Percent e: 1.234500e-05