StringJoin

s1 <> s2 <> ... can join a list of strings into a single string.

Attributes[StringJoin] := {Flat, OneIdentity, Protected}

Simple examples

In[1]:= "Hello" <> " " <> "World"
Out[1]= "Hello World"

In[2]:= "If a=2, then " <> ToString[a^2, InputForm] <> "=" <> ToString[((a^2)) /. ((a -> 2)), InputForm]
Out[2]= "If a=2, then a^2=4"

Further examples

The StringJoin of nothing is the empty string:

In[1]:= StringJoin[]
Out[1]= ""

If StringJoin receives any non-string arguments, the expression does not evaluate:

In[2]:= "Hello" <> 5
Out[2]= "Hello" <> 5

This function takes List arguments as well:

In[3]:= StringJoin[{"a", "b", "c"}]
Out[3]= "abc"