CODEWITHSUNDEEP
erlang
ㄨPobre
ㄨPobre

Reputation: 27

How to put a string in an if statement in erlang?

-module(prac).
-export([test_if/1]).

test_if(A) ->
    if
        A == sir_boss ->
            team_leader;
        A == worker1 or worker2 or worker3 or worker4 ->
            regular;
        A == me ->
            intern
    end.

how do I properly put list or string in an if statement?

Upvotes: 1

Views: 482

Answers (1)

Steve Vinoski
Steve Vinoski

Reputation: 20004

It's not clear whether you want to compare strings or return them; I'll assume you're trying to compare them.

Your code is comparing the variable A to various atoms. If you want to compare strings, you can do it using an if like this:

-module(prac).
-export([test_if/1]).

test_if(A) ->
    if
        A == "sir_boss" ->
            team_leader;
        A == "worker1"; A == "worker2";
        A == "worker3"; A == "worker4" ->
            regular;
        A == "me" ->
            intern
    end.

The semicolons in the worker comparison clause essentially act as orelse.

Running this in an Erlang shell shows that it seems to behave as expected:

1> prac:test_if("me").
intern
2> prac:test_if("worker4").
regular

But a better approach than using an if is to pattern-match arguments in function heads:

test_if("sir_boss") -> team_leader;
test_if("worker1") -> regular;
test_if("worker2") -> regular;
test_if("worker3") -> regular;
test_if("worker4") -> regular;
test_if("me") -> intern.

This is clearer and more idiomatic than using an if.

Upvotes: 2

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