Function Details : strtod

doublestrtod(const char * str,char ** endptr) ;

Return Type : double

Double-precision floating point (±1.7E±308, ~15 decimal digits)

Read about return values of strtod function .

1st Parameter Type : const char *

Pointer to read-only string

1st Parameter

Pointer to the null-terminated string to be converted to a `double`. The string may represent a floating-point value, optionally preceded by whitespace and a sign.

2nd Parameter Type : char **

A pointer to a pointer to a null-terminated string. Commonly used in functions like `strtol` and `strtok_r` to store the address of the first invalid character or to maintain state across function calls.

2nd Parameter

Pointer to a pointer that will be set to the character after the last valid character used in the conversion. Can be `NULL` if this information is not needed.

Read more about parameters of strtod in parameters section

The strtodfunction in C language Converts the initial portion of the string to a double-precision floating-point number.

The strtod function converts the initial portion of the string pointed to by nptr to a double. It skips leading whitespace, converts the subsequent characters as part of the number, and stops at the first character it cannot recognize as part of a number. If endptr is not NULL, it stores the address of the first invalid character in *endptr.

The strtodfunction takes 2 parameters:

•
const char * `str`: Pointer to the null-terminated string to be converted to a `double`. The string may represent a floating-point value, optionally preceded by whitespace and a sign.
•
char ** `endptr`: Pointer to a pointer that will be set to the character after the last valid character used in the conversion. Can be `NULL` if this information is not needed.

Converts the initial portion of the string `str` to a `double` value. If `endptr` is not `NULL`, it is set to point to the first character after the converted value. Returns the converted `double` value or `0.0` if no valid conversion could be performed. Handles special values like `INF` or `NAN` if supported.

The strtod function return value :

Returns the converted double value
If no conversion could be performed, 0
0 is returned
If the correct value is outside the range of representable values, HUGE_VAL (with the correct sign) is returned and errno is set to ERANGE

Output

This example demonstrates basic usage of strtod to convert a string to a double and identify the remainder of the string.