摘要：function ToTrans(a) { var b = 9.999999999999E10, f = "\u96f6", h = "\u58f9", g = "\u8d30", e = "\u53c1", k = "\u8086", p = "\u4f0d", q = "\u9646", r = "\u67d2", s = "\u634c", t = "\u7396", l = "\ 阅读全文

摘要：（1）typeof用法typeof的运算数未定义,返回的就是 "undefined".运算数为数字 typeof(x) = "number"字符串 typeof(x) = "string"布尔值 typeof(x) = "boolean"对象,数组 和nulltypeof(x) = "object"函数 typeof(x) = "function"（2）js判断是否为空var exp = null;if (!exp&& typeof(exp)!="u 阅读全文