The C library function double atof(const char *str) converts the string argument str to a floating-point number (type double).
Following is the declaration for atof() function.
double atof(const char *str)
str − This is the string having the representation of a floating-point number.
This function returns the converted floating point number as a double value. If no valid conversion could be performed, it returns zero (0.0).
The following example shows the usage of atof() function.
#include <stdio.h> #include <stdlib.h> #include <string.h> int main () { float val; char str[20]; strcpy(str, "98993489"); val = atof(str); printf("String value = %s, Float value = %f\n", str, val); strcpy(str, "tutorialspoint.com"); val = atof(str); printf("String value = %s, Float value = %f\n", str, val); return(0); }
Let us compile and run the above program that will produce the following result −
String value = 98993489, Float value = 98993488.000000 String value = tutorialspoint.com, Float value = 0.000000