What is the difference between <%, <%=, <%# and -%> in ERB in Rails?

Question

Can some one please describe the usage of the following characters which is used in ERB file:

<%   %>
<%=  %>
<%  -%>
<%#  %>
         


        

Answer 1

<% %> executes the code in there but does not print the result, for eg:
We can use it for if else in an erb file.

<% temp = 1 %>
<% if temp == 1%>
  temp is 1
<% else %>
  temp is not 1
<%end%>  

Will print temp is 1

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<%= %> executes the code and also prints the output, for eg:
We can print the value of a rails variable.

<% temp = 1 %>
<%= temp %>  

Will print 1

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<% -%> It makes no difference as it does not print anything, -%> only makes sense with <%= -%>, this will avoid a new line.

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<%# %> will comment out the code written within this.