下面是一段计算器的+ -代码,有不懂 public string getResult(string Fnumber, string Snumber, string Op)
{
double res = 0;
switch (Op)
{
case "+":
try
{
res = Convert.ToDouble(Fnumber) + Convert.ToDouble(Snumber); (这句的+运算一点懂又不懂,Conver是什么,怎么用的?)
}
catch (Exception e)
{
throw e;
}
break;
case "-":
try
{
res = Convert.ToDouble(Fnumber) - Convert.ToDouble(Snumber);
}
catch (Exception e)
{
throw e;
}
break;
{
double res = 0;
switch (Op)
{
case "+":
try
{
res = Convert.ToDouble(Fnumber) + Convert.ToDouble(Snumber); (这句的+运算一点懂又不懂,Conver是什么,怎么用的?)
}
catch (Exception e)
{
throw e;
}
break;
case "-":
try
{
res = Convert.ToDouble(Fnumber) - Convert.ToDouble(Snumber);
}
catch (Exception e)
{
throw e;
}
break;
主要用来类型转换 Convert.ToDouble(Fnumber) + Convert.ToDouble(Snumber); 把2个string类型的数转换成double
顾名思意,在此类中有大量对某一类型的变量转换成另一种类型的方法
而且都是静态的方法
Convert.ToDouble(Fnumber)
这句很明显是将string类型转换成double类型