scanf收集了错误的输入 [英] scanf is collecting the wrong input

问题描述

 #include<stdio.h> 
 int main(void)
 {
      double c;
      scanf("%f", &c);
      printf("%f", c);
 }

这是我尝试编写的程序的摘录，但我同样简单的事情也会遇到同样的问题。当我运行此命令并输入 1.0时，它会打印出 0.007812。我看过以前的几个问题，这些问题与我的相似，找不到合适的答案。

This is an exerpt from a program I'm attempting to write, but I get the same issue with something this simple. when I run this, and enter "1.0", it prints out "0.007812". I've looked at several previous questions that were similar to mine and could not find an appropriate answer.

推荐答案

您需要使用％lf 为两倍。

这是clang编译器发出的警告。

This is the warning from clang compiler.

warning：format指定类型为'float *'，但参数类型为'double *'[-Wformat]
scanf（％f，& c）;

warning: format specifies type 'float *' but the argument has type 'double *' [-Wformat] scanf("%f", &c);

这是扫描引用。格式为％[*] [width] [length]指定符。 浮点数的说明符是 f 。因此，我们使用％f 来读取 float x 。要读取 double x ，我们需要将长度指定为 l 。组合格式为％lf 。

Here is the scanf reference. It's format is %[*][width][length]specifier. The specifier for 'floating point number' is f. So we use %f to read float x. To read double x, we need to specify the length as l. Combined the format is %lf.

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