C library functions - atof ()

C standard library - <stdlib.h>

description

C library functionsdouble atof (const char * str) to convert a string argument strpoints to a floating-point number (of type double type).

statement

Here it is () declare atof function.

double atof(const char *str)

parameter

• str - the string to be converted to floating-point number.

return value

The function returns the converted double-precision floating-point number, if there is no implementation of an effective conversion, it returns zero (0.0).

Examples

The following example demonstrates the atof () function is used.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
   float val;
   char str[20];
   
   strcpy(str, "98993489");
   val = atof(str);
   printf("字符串值 = %s, 浮点值 = %f\n", str, val);

   strcpy(str, "w3cschool.cc");
   val = atof(str);
   printf("字符串值 = %s, 浮点值 = %f\n", str, val);

   return(0);
}

Let's compile and run the above program, which will result in the following:

字符串值 = 98993489, 浮点值 = 98993488.000000
字符串值 = w3cschool.cc, 浮点值 = 0.000000

C standard library - <stdlib.h>