JavaScript将UPC转换成ISBN的代码
if (indexisbn.indexOf("978") == 0) { isbn = isbn.substr(3,9); var xsum = 0; var add = 0; var i = 0; for (i = 0; i < 9; i++) { add = isbn.substr(i,1); xsum += (10 - i) * add; } xsum %= 11; xsum = 11 - xsum; if (xsum == 10) { xsum = "X"; } if (xsum == 11) { xsum = "0"; } isbn += xsum; }