📅 Date: Jan 25, 2026
🔥 Topic: Introduction to Strings, Char Arrays & ASCII

🧵 What is a String?

So far, I've dealt with numbers. But apps need text (Names, Messages, Emails). In C++, a String is basically a sequence of characters.

The Array Connection

Technically, a string is just an Array of Characters.
If I write string name = "Sahil";, memory looks like this:

Wait, what is \0?
It's called the Null Terminator. It tells the computer "STOP! The string ends here." Without it, the computer would keep reading garbage memory.

🔢 The ASCII Code (Computer's Secret)

Computers don't understand 'A' or 'B'. They only understand numbers. Every character has a numeric ID called an ASCII Value.

  • 'A' - 'Z': 65 to 90
  • 'a' - 'z': 97 to 122
  • '0' - '9': 48 to 57

💻 Day 25 Code: Hacking Characters

I wrote a program to reveal the hidden numbers behind characters. 

#include <iostream>
using namespace std;

int main() {
    char c = 'A';
    cout << "Character: " << c << endl;
    
    // Typecasting to int reveals ASCII
    cout << "ASCII Value: " << int(c) << endl; 

    // Moving char like numbers
    char next = c + 1; 
    cout << "Next Character (A+1): " << next << endl; // Prints 'B'

    return 0;
}

💭 Thoughts

Knowing that 'a' is just 97 is a game changer. I can now convert Uppercase to Lowercase just by adding 32 to the ASCII value!