+                        Addition and Concatenation

    Addition

 exp1 + exp2

    The + operator performs addition. If the expression involves operands
    of more than one precision, all operands are converted to the same
    level--that of the highest-precision operand in the expression--before
    the expression is evaluated.

   exp1,exp2    Any numeric expression.


    Concatenation

 str1 + str2

    The + operator also performs concatenation on string expressions. The
    result is a string composed of str1 followed by str2.

   str1,str2    Any string expression.