Erlang - Numbers

In Erlang there are 2 types of numeric literals which are integers and floats. Following are some examples which show how integers and floats can be used in Erlang.

Integer − An example of how the number data type can be used as an integer is shown in the following program. This program shows the addition of 2 Integers.

Example

-module(helloworld). 
-export([start/0]). 

start() -> 
   io:fwrite("~w",[1+1]).

The output of the above program will be as follows −

Output

2

Float − An example of how the number data type can be used as a float is shown in the following program. This program shows the addition of 2 Integers.

Example

-module(helloworld).
-export([start/0]). 

start() -> 
   io:fwrite("~w",[1.1+1.2]).

The output of the above program will be as follows −

Output

2.3

Displaying Float and Exponential Numbers

When using the fwrite method to output values to the console, there are formatting parameters available which can be used to output numbers as float or exponential numbers. Let’s look at how we can achieve this.

Example

-module(helloworld). 
-export([start/0]). 

start() -> 
   io:fwrite("~f~n",[1.1+1.2]), 
   io:fwrite("~e~n",[1.1+1.2]).

The output of the above program will be as follows −

Output

2.300000
2.30000e+0

The following key things need to be noted about the above program −

• When the ~f option is specified it means that the argument is a float which is written as [-]ddd.ddd, where the precision is the number of digits after the decimal point. The default precision is 6.

• When the ~e option is specified it means that the argument is a float which is written as [-]d.ddde+-ddd, where the precision is the number of digits written. The default precision is 6.

Mathematical Functions for Numbers

The following mathematical functions are available in Erlang for numbers. Note that all the mathematical functions for Erlang are present in the math library. So all of the below examples will use the import statement to import all the methods in the math library.