Javatpoint Logo
Javatpoint Logo

Convert Scientific Notation to Decimal form in C++

In this article, we will discuss how to convert Scientific Notation to Decimal Form in C++.

The scientific notation is in the form of a*(10) ^b. Where a is the coefficient, b is the exponent. The product of the coefficient and the exponent gives the decimal form where the number expresses values using the powers of 10, with each digit position indicating the power of 10.

Usually, scientific notation is used for expressing very large or minimal numbers in a concise and standardized form.

Example 1:

Scientific notation: 3.14 X 10 ^5

In this example, the coefficient is 3.14, and the exponent is 5.

After that, we calculate the decimal form

3.14 X 100000 = 314000

Another example to illustrate the conversion

Scientific notation: 23.2 X 10 ^-4

In this example, the coefficient is 23.2 and the exponent is -4, and then the decimal format is 0.00232.


Let us take a program to convert scientific notation to decimal format in C++.


Enter a number in scientific notation: 125.e4
Decimal representation: 1250000.000000000000000


Variables in the program:

  • Scientific notation: A string variable is used to store the user input for the number in scientific notation.
  • Value: A double variable is used in the scientificToDecimal function to store the converted decimal value.

Functions in the program:

  • scientificToDecimal(const string &scientificNotation): It converts a number in scientific notation to decimal format. It uses a stringstream (iss) to handle the input string and returns the decimal value.
  • main(): The main() function where the program starts execution. It prompts the user for input, calls scientificToDecimal to convert it, and displays the result.
  • The program is designed to convert the numbers from scientific notation to decimal format. It consists of two components: the scientificToDecimal function and the main function. The scientificToDecimal function is responsible for the actual conversion process. It takes a string as an argument, which represents the scientific notation. In the function, a string string stream is created to hold the input string. After that, it uses >> to get a double value from the given string. If it cannot extract the double value, an error message is displayed using the cerr in-built function, and the function returns 0; otherwise, it will convert the scientific notation to the decimal value.
  • In the main function, the string representing the scientific notation is taken from the user and is sent to the scientificToDecimal function for conversion. Finally, the answer will be printed.
  • Fixed and setprecision manipulators are mainly used with the output stream to control the formatting of floating point numbers. They are part of the <iomanip> header fixed manipulator, which is used to force the floating-point number to be displayed in fixed-point notation.
  • setprecision manipulator: It is used to set the precision, which is the number of decimal places for floating-point numbers.

This program is a simple utility for converting scientific notation to decimal format. It showcases fundamental C++ concepts such as string manipulation, input/output operations, and the use of functions.


In conclusion, the C++ program and the accompanying explanation offer a concise and practical solution for converting numbers from scientific notation to decimal form. Scientific notation, represented as a×10^b, provides a standardized way to express huge and small numbers, where the coefficient (a) and exponent (b) play crucial roles.

The program exemplifies the principles of C++ programming, showcasing the usage of essential components such as string manipulation, input/output operations, and function implementation. By taking user input as scientific notation, the program employs a string stream to extract the coefficient and exponent, facilitating a straightforward conversion to decimal form.

This utility holds significance in various scientific and engineering applications where precise representation of values is essential.

Youtube For Videos Join Our Youtube Channel: Join Now


Help Others, Please Share

facebook twitter pinterest

Learn Latest Tutorials


Trending Technologies

B.Tech / MCA