How To Add Decimals To C++

This article volition show yous how to set decimal precision in C programming language. Showtime, we volition define precision, and so, we will expect into multiple examples to show how to set decimal precision in C programming.

Decimal Precision in C

The integer blazon variable is unremarkably used to hold the whole number and float blazon variable to hold the real numbers with fractional parts, for example, 2.449561 or -1.0587. Precision determines the accurateness of the real numbers and is denoted past the dot (.) symbol. The Exactness or Accuracy of real numbers is indicated by the number of digits subsequently the decimal point. So, precision ways the number of digits mentioned afterward the decimal betoken in the float number. For example, the number 2.449561 has precision six, and -1.058 has precision iii.

As per IEEE-754 unmarried-precision floating point representation, in that location are a full of 32 bits to store the existent number. Of the 32 $.25, the nearly meaning bit is used as a sign bit, the post-obit viii bits are used as an exponent, and the following 23 bits are used as a fraction.

In the case of IEEE-754 double-precision floating point representation, there are a total of 64 bits to store the existent number. Of the 64 bits, the most significant bit is used as a sign bit, the following eleven $.25 are used as an exponent, and the post-obit 52 bits are used as a fraction.

Nevertheless, when printing the existent numbers, it is necessary to specify the precision (in other words, accurateness) of the real number. If the precision is not specified, the default precision will be considered, i.eastward., half-dozen decimal digits later the decimal point. In the following examples, we volition testify y'all how to specify precision when printing floating-bespeak numbers in the C programming language.

Examples

Now that you have a basic understanding of precision, allow us expect at a couple of examples:

1. Default precision for float
2. Default precision for double
3. Set precision for bladder
4. Set precision for double

Example 1: Default Precision for Float

This case shows that the default precision is fix to six digits after the decimal indicate. Nosotros accept initialized a float variable with the value 2.7 and printed it without explicitly specifying the precision.

In this case, the default precision setting will ensure that half dozen digits afterward the decimal point are printed.

#include <stdio.h>

int main( )
{
float f = 2.7 ;

printf ( "\northValue of f = %f \northward" , f) ;
printf ( "Size of bladder = %ld \n" , sizeof ( float ) ) ;

return 0 ;
}

Instance 2: Default Precision for Double

In this example, you volition see that the default precision is prepare to six digits after the decimal point for double type variables. We take initialized a double variable, i.eastward., d, with the value ii.vii and printed information technology without specifying the precision. In this case, the default precision setting will ensure that six digits after the decimal betoken are printed.

#include <stdio.h>

int master( )
{
double d = ii.7 ;

printf ( "\northwardValue of d = %lf \n" , d) ;
printf ( "Size of double = %ld \n" , sizeof ( double ) ) ;

return 0 ;
}

Example 3: Set Precision for Float

Now, nosotros will show you how to set precision for bladder values. We have initialized a float variable, i.e., f, with the value 2.7, and printed it with various precision settings. When we mention "%0.4f" in the printf argument, this indicates that we are interested in printing four digits after the decimal point.

#include <stdio.h>

int chief( )
{
float f = 2.7 ;

/* set precision for float variable */
printf ( "\due northValue of f (precision = 0.ane) = %0.1f \northward" , f) ;
printf ( "\nValue of f (precision = 0.2) = %0.2f \n" , f) ;
printf ( "\northValue of f (precision = 0.3) = %0.3f \n" , f) ;
printf ( "\nValue of f (precision = 0.four) = %0.4f \n" , f) ;

printf ( "\nValue of f (precision = 0.22) = %0.22f \n" , f) ;
printf ( "\northwardValue of f (precision = 0.23) = %0.23f \due north" , f) ;
printf ( "\due northValue of f (precision = 0.24) = %0.24f \n" , f) ;
printf ( "\nValue of f (precision = 0.25) = %0.25f \n" , f) ;
printf ( "\northwardValue of f (precision = 0.40) = %0.40f \n" , f) ;

printf ( "Size of bladder = %ld \n" , sizeof ( float ) ) ;

return 0 ;
}

Example 4: Set up Precision for Double

In this example, nosotros will see how to set precision for double values. We take initialized a double variable, i.eastward., d, with the value ii.7 and printed it with various precision settings. When we mention "%0.52f" in the printf argument, this indicates that we are interested in printing 52 digits after the decimal bespeak.

#include <stdio.h>

int main( )
{
float f = 2.vii ;

/* prepare precision for bladder variable */
printf ( "\nValue of f (precision = 0.one) = %0.1f \n" , f) ;
printf ( "\nValue of f (precision = 0.2) = %0.2f \n" , f) ;
printf ( "\nValue of f (precision = 0.3) = %0.3f \n" , f) ;
printf ( "\nValue of f (precision = 0.iv) = %0.4f \n" , f) ;

printf ( "\nValue of f (precision = 0.22) = %0.22f \due north" , f) ;
printf ( "\nValue of f (precision = 0.23) = %0.23f \north" , f) ;
printf ( "\nValue of f (precision = 0.24) = %0.24f \n" , f) ;
printf ( "\nValue of f (precision = 0.25) = %0.25f \n" , f) ;
printf ( "\northwardValue of f (precision = 0.xl) = %0.40f \north" , f) ;

printf ( "Size of float = %ld \n" , sizeof ( float ) ) ;

return 0 ;
}

Decision

Precision is a very of import factor for representing a real number with adequate accuracy. The c programming language provides the mechanism to control the accuracy or exactness of a real number. However, we cannot change the actual precision of the real number. For instance, the fraction office of a 32-fleck single-precision floating-point number is represented past 23 bits, and this is fixed; we cannot change this for a particular system. We can just decide how much accuracy we desire by setting the desired precision of the existent number. If we need more accuracy, we can ever use the 64-bit double-precision floating-point number.

About the author

I am a passionate software engineer and blogger. I take done my Masters in Software Engineering from BITS PILANI Academy, Republic of india. I have very adept experience in real-fourth dimension software evolution and testing using C, C++, and Python. Follow me at thecloudstrap.com.