string format operator

The string format operator ':' requires that the left hand operand be a valid format string ('C' format string) and that the right hand operand be any other typed value

e.g

j   =   15

A   =   "fred_%d_x" : j

will set   A   to the string   "fred_15_x"

BEWARE that coercion will be performed to ensure that the right hand operand matches the format specifier

e.g.

j   =   3.1416

A   =   "pi=%d" : j

will set   A   to the string   "pi=3"

A   =   "pi=%s" : j

will set   A   to the string   "pi=3.1416"