Have you ever needed to create a variable containing only the first character of a character variable? This DATA step shows four different ways to retrieve only the first character. Each new variable (A1, A2, A3, A4) contains only the letter 'F', however the lengths of these four variables are NOT all the same.

data one;
    name='Fred';
    a1 = substr(name,1,1);
    a2 = first(name);
    substr(a3,1,1) = name;
    length a4 $1;
    a4 = name; 
run;