Erlang - If statement


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The first decision making statement we will look at is the ‘if’ statement. The general form of this statement in Erlang is shown in the following program −

Syntax

if
condition ->
   statement#1;
true ->
   statement #2
end.

In Erlang, the condition is an expression which evaluates to either true or false. If the condition is true, then statement#1 will be executed else statement#2 will be executed.

If statement

The following program is an example of the simple if expression in Erlang −

Example

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

start() -> 
   A = 5, 
   B = 6, 
   
   if 
      A == B -> 
         io:fwrite("True"); 
      true -> 
         io:fwrite("False") 
   end.

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

  • The expression being used here is the comparison between the variables A and B.

  • The -> operator needs to follow the expression.

  • The ; needs to follow statement#1.

  • The -> operator needs to follow the true expression.

  • The statement ‘end’ needs to be there to signify the end of the ‘if’ block.

The output of the above program will be −

Output

False
erlang_decision_making.htm
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