将字符串转换在C双变量 [英] converting string to a double variable in C

问题描述

我写了下面的code ....应该转换为字符串，如88为双精度值88和打印

I have written the following code....It should convert a string like "88" to double value 88 and print it

void convertType(char* value)
{
   int i = 0;
   char ch;
   double ret = 0;
   while((ch = value[i] )!= '\0')
   {
      ret = ret*10 +(ch - '0');
      ++i;
   }
   printf("%d",ret);//or %f..what is the control string for double?
}



//input string :88

但它总是输出0 ...但是，当我改变RET为int类型...它正常工作......当类型为float或double，它打印零...所以为什么我收到这个暧昧结果如何？

But it always prints 0...But when i change type of ret to int ...it works fine...when the type is float or double,it prints zero...so why am i getting this ambiguous results?

推荐答案

使用的sscanf ：

char str[] = "12345.56";
double d;

sscanf(str, "%lf", &d);

printf("%lf", d);

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