C library function - strtod()

Description

The C library function double strtod(const char *str, char **endptr) converts the string pointed to by the argument str to a floating-point number (type double). If endptr is not NULL, a pointer to the character after the last character used in the conversion is stored in the location referenced by endptr.

Declaration

Following is the declaration for strtod() function.

double strtod(const char *str, char **endptr)

Parameters

• str − This is the value to be converted to a string.

• endptr − This is the reference to an already allocated object of type char*, whose value is set by the function to the next character in str after the numerical value.

Return Value

This function returns the converted floating point number as a double value, else zero value (0.0) is returned.

Example

The following example shows the usage of strtod() function.

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

int main () { 
   char str[30] = "20.30300 This is test";
   char *ptr;
   double ret;

   ret = strtod(str, &ptr);
   printf("The number(double) is %lf\n", ret);
   printf("String part is |%s|", ptr);

   return(0);
}

Let us compile and run the above program that will produce the following result −

The number(double) is 20.303000
String part is | This is test|