//1.值类型的转换注意大小(隐式转换和强制转换)long chang = 56595959; int int4 = 23; chang = int4; int4 = (int)chang;
//2.引用类型的强制转换 Animal a = new Animal(); Dog d = null; //d = (Dog)a;
//2.1 引用类型的隐式转换 a = d; //数据类型中引用类型string的问题 string aa = "abc"; aa = "cde"; string bb = "def"; aa += bb; //如果要拼接大量的字符串,就使用StringBuilder,比如拼接SQL StringBuilder sb = new StringBuilder("a"); sb.Append("b"); sb.Append("c"); sb.Append("d"); string jieguo = sb.ToString(); //var names = []; //names.push("a"); //names.push("b"); //names.push("c"); //var nj = names.join('');