First character

Challenge

Return the first character of a string, treating the empty string safely.

Task

Implement char first_char(const char *s) that returns the first character of s, or '\0' if s is empty. No main — the grader calls it.

Input

A NUL-terminated string s.

Output

Returns the first character, or '\0' (0) when s is empty.

Example

first_char("hi")   ->   'h'
first_char("x")    ->   'x'
first_char("")     ->   '\0'

Edge cases

• The empty string starts with '\0', so s[0] already covers it.

Input format

A NUL-terminated string s.

Output format

The first character, or '\0' if s is empty.

Constraints

s is a null-terminated string with at least one character (s[0] != '\0'). Never NULL in tests.

Starter code

char first_char(const char *s) {
    /* TODO */
    return 0;
}

Common mistakes

Trying to return a pointer (char*) instead of the character value (char).

Edge cases to handle

Single-character string, string starting with whitespace, string starting with punctuation.