Write a program that prints the sum of all numbers from 1 to 100.

Program in C

#include <stdio.h>

int main() {
    int sum = 0;
    int i;

    for (i = 1; i <= 100; i++) {
        sum += i;
    }

    printf("The sum of all numbers from 1 to 100 is: %d\n", sum);

    return 0;
}

Explanation:

• In this program, we declare an integer variable sum and initialize it to 0.
• The for loop runs from 1 to 100, and in each iteration, it adds the value of i to the sum variable using the += operator.
• After the loop, we use printf to display the final value of sum.

Output:

The sum of all numbers from 1 to 100 is: 5050

Program in Java

public class SumHundred {
    public static void main(String[] args) {
        int sum = 0;
        int i;

        for (i = 1; i <= 100; i++) {
            sum += i;
        }

        System.out.println("The sum of all numbers from 1 to 100 is: " + sum);
    }
}

Explanation:

1. The public class SumHundred defines a class named SumHundred, which is the entry point for the Java program.
2. The public static void main(String[] args) method is the main method, which serves as the starting point for the execution of the program.
3. int sum = 0; declares and initializes an integer variable sum to 0, which will store the sum of numbers.
4. int i; declares an integer variable i which will be used as a loop counter in the for loop.
5. for (i = 1; i <= 100; i++) is a for loop that starts with i being 1, executes the loop body as long as i is less than or equal to 100, and increments i by 1 in each iteration.
6. Inside the loop body, sum += i; adds the value of i to the sum variable, effectively summing up all the numbers from 1 to 100.
7. System.out.println(“The sum of all numbers from 1 to 100 is: ” + sum); prints the result to the console, concatenating the sum value with the given string.

The sum of all numbers from 1 to 100 is: 5050