Understand how strings are represented in C as null-terminated arrays of characters.
In the C programming language, there is no built-in string data type. Instead, a string is represented and manipulated as a one-dimensional array of characters. However, there's a crucial convention that distinguishes a character array that is a string from one that is just a collection of characters: the null terminator. A C-style string is a sequence of characters stored in an array that is terminated by a null character, which is written as '\u0000' (or '\0'). This special character has an ASCII value of 0 and acts as a sentinel, marking the end of the string. This null terminator is vital because standard library functions that work with strings, like printf with %s, strlen, or strcpy, rely on it to know where the string ends. Without it, these functions would continue reading memory past the end of the array, leading to undefined behavior and potential program crashes. When you declare and initialize a string using a string literal (text in double quotes), the compiler automatically adds the null terminator for you. For example, char greeting[] = "Hello"; creates an array of 6 characters: 'H', 'e', 'l', 'l', 'o', and '\u0000'. You must always ensure your character arrays are large enough to hold all the characters of your string plus the null terminator. Forgetting to account for this extra character is a very common source of bugs for new C programmers.