The strtonum Statement
The strtonum statement parses its input string (third) argument into a numeric output (first) argument, advancing an offset output (second) argument past the numeric string. The initial input offset (fourth) argument determines where the string parsing begins. The default (fifth) argument is the value that is returned by the statement if an error occurs while parsing the string. The syntax of the strtonum statement is shown below.
// parse string into num
strtonum value, idx, strValue, idx, nZero