How are strings represented in C?

A string is just a char array (ASCII-encoded) whose end is marked by a \0 null byte — there's no separate string type or stored length.

* "Hello" is five characters plus a \0 terminator — 6 bytes, with no separately stored length. *

// Actually 6 bytes: H e l l o \0
char str[] = "Hello";

In memory:

The null terminator \0:

• Marks the end of the string
• ASCII value 0 (not the character '0' which is 0x30)
• Functions like strlen() count until they hit \0

Escape sequences:

Safe string handling:

char str[128];
// Prevents overflow
snprintf(str, sizeof(str), "%d arguments\n", argc);
// NOT sprintf(str, ...) which can overflow!

Go deeper:

• C string handling — Wikipedia — the null-terminated convention, the standard string functions, and their pitfalls.