What is the precision of floating point in C++?

In C++, the size of the floating point number is either 4-byte or 8-bytes. So it can store up to few decimal places. For example, the 1/3 = 0.333333…… Up to infinity. If we store it inside floating type variable, then it will store some significant digits. The default value is 6. So normally floating point numbers in C++ can display up to 6 decimal places.

We can change the size of the precision using setprecision. This is present inside the iomanip header file. Let us see one example to get the idea.

Example Code

#include <iostream>
#include <iomanip>
using namespace std;
int main() {
   double x = 2.3654789d;
   cout << "Print up to 3 decimal places: " << setprecision(3) << x << endl;
   cout << "Print up to 2 decimal places: " << setprecision(2) << x << endl;
   cout << "Print up to 7 decimal places: " << setprecision(7) << x << endl;
}

Output

Print up to 3 decimal places: 2.365
Print up to 2 decimal places: 2.37
Print up to 7 decimal places: 2.3654789

Ankith Reddy

Published on 28-May-2019 12:29:19

• Related Questions & Answers
• Precision of floating point numbers in C++ (floor(), ceil(), trunc(), round() and setprecision())
• How to deal with floating point number precision in JavaScript?
• What are C++ Floating-Point Constants?
• What are floating point literals in C#?
• C++ Floating Point Manipulation
• What is Floating-Point Representation in Computer Architecture?
• Reinterpret 64-bit signed integer to a double-precision floating point number in C#
• Convert the specified double-precision floating point number to a 64-bit signed integer in C#
• Floating point comparison in C++
• What is the difference between integer and floating point literals in Java?
• Signed floating point numbers
• Comparison of floating point values in PHP.
• Floating-point hexadecimal in Java
• Fixed Point and Floating Point Number Representations
• Get the hyperbolic arc-cosine of a floating-point value in C#