6.9 True and False in awk

Many programming languages have a special representation for the concepts of "true" and "false." Such languages usually use the special constants true and false, or perhaps their uppercase equivalents. However, awk is different. It borrows a very simple concept of true and false from C. In awk, any nonzero numeric value or any non-empty string value is true. Any other value (zero or the null string "") is false. The following program prints `A strange truth value' three times:

BEGIN { if (3.1415927) print "A strange truth value" if ("Four Score And Seven Years Ago") print "A strange truth value" if (j = 57) print "A strange truth value" }

There is a surprising consequence of the "nonzero or non-null" rule: the string constant "0" is actually true, because it is non-null. (d.c.)