How can I transform a String, which is a numerical value, to an Integer?

Some additional picky details:

The unary + operator is a numeric operator so it converts its operand to a number.  If a string operand starts with a fractional number then unary + produces a fractional number (in its canonical numeric form) and it throws away any unneeded characters.  If you want your numeric result to be an integer then you need to throw away the fractional digits by doing an integer-division by 1.  Since the integer-division operator, \, is a numeric operator it always converts its operands to numbers so you no longer need the unary + to do the conversion of a string to numeric representation.  E.g.s:

USER>w "0012.543000abc"   
0012.543000abc
USER>w +"0012.543000abc"
12.543
USER>w +"0012.543000abc"\1
12
USER>w "0012.543000abc"\1 
12