The ASCII codes for lowercase letters "a-z" and uppercase letters "A-Z" are consistent across various systems and programming languages, including C/C++. This consistency ensures that the ASCII codes of these characters remain the same on any system that supports ASCII encoding. The ASCII ranges for uppercase and lowercase letters is given below:



ASCII Range for Upper and Lowercase Letters

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Moreover, as the ASCII codes for these characters are sequential and ascending, we can use a loop in C/C++ to iterate through, as follows:

#include <iostream>
using namespace std;

int main() {
    char symbol;
    
    // print ASCII values of A-Z
    for (symbol = 'A'; symbol <= 'Z'; symbol++) 
    {
        cout << symbol << ": " << (int)symbol <<endl;
    }

    // print ASCII values of a-z
    for (symbol = 'a'; symbol <= 'z'; symbol++) 
    {
        cout << symbol << ": " << (int)symbol <<endl;
    }

    return 0;
}


#include <stdio.h>


int main() {
    char symbol;

    // print ASCII values of A-Z
    for (symbol = 'A'; symbol <= 'Z'; symbol++) 
    {
        printf("%c: %d\n", symbol, (int)symbol);
    }

    // print ASCII values of a-z
    for (symbol = 'a'; symbol <= 'z'; symbol++) 
    {
        printf("%c: %d\n", symbol, (int)symbol);
    }

    return 0;
}


# Explanation

* **Line 5:** A variable named `symbol` of type `char` is declared to store characters.

* **Line 8–11:** This block of code represents a `for` loop that iterates over the uppercase letters from `A` to `Z`. It initializes symbol with `A` and continues the loop as long as symbol is less than or equal to `Z`. In each iteration, it prints the current value of `symbol`, followed by a colon and the ASCII value of the character obtained by casting `symbol` to an integer using `(int)symbol`. 

* **Line 14–17:** This block of code represents another `for` loop that iterates over the lowercase letters from `a` to `z`. It initializes `symbol` with `a` and continues the loop as long as `symbol` is less than or equal to `z`. In each iteration, it prints the current value of `symbol`, followed by a colon and the ASCII value of the character obtained by casting `symbol` to an integer using `(int)symbol`.


Does C and C++ ensure the ASCII codes for a-z and A-Z characters?

The ASCII codes for 'a-z' and 'A-Z' are consistent in C/C++, enabling sequential character iteration.

Upper letters	ASCII values range
A–Z	65–90
Lower letters	ASCII values range
a–z	97–122