6.6. Array Example – Sum of Elements

public class SumExample {

In Java, classes are blueprints for creating objects. Here, we define a public class named SumExample. The public keyword indicates that the class is accessible from other classes. The name SumExample is an identifier that refers to this class. This is the foundational step in Java programming, where we start building our program.

Think of a class like a recipe. Just like a recipe outlines the steps and ingredients needed to make a dish, a class outlines the attributes and functionalities of an object.

public static void main(String[] args) {

This line defines the main method where Java programs begin execution. The method signature includes public, meaning it can be called from anywhere; static, indicating it belongs to the class rather than an instance; and void, indicating it does not return any value. The parameter String[] args allows the program to accept arguments from the command line.

Imagine the main method as the front door of a house. Just as you enter through the front door to access the home, the Java Virtual Machine (JVM) enters through the main method to start executing the program.

int[] marks = {90, 85, 80};

Here, we create an integer array named marks and initialize it with three values: 90, 85, and 80. The int[] indicates that marks is an array of integers. The curly braces {} are used to list the initial values directly when creating the array.

Think of an array like a container with labeled compartments. Each compartment can store a single item—in this case, each grade. We’re filling our container with specific grades from the start.

int sum = 0;
for (int m : marks) {
    sum += m;
}

This chunk initializes a variable sum to 0, which will hold the total marks. The for loop iterates through each element m in the marks array. During each iteration, the current value of m is added to sum. This way, we accumulate the total of all marks in the array.

Imagine if you were collecting points in a game. You start with zero points, and each time you earn points from a level, you add those to your total score. That’s exactly what we’re doing here—summing up marks one by one.

System.out.println("Total Marks = " + sum);
}
}

Finally, this line outputs the total marks accumulated in the sum variable to the console. The System.out.println statement prints the string formatted with the total marks. The enclosing braces } close the main method and class declaration.

Think of this step as announcing your total score after finishing a game. Just like you would tell others how many points you earned, this program prints the total marks to inform you of your performance.

Total Marks = 255

After running the program, the output shows Total Marks = 255. This conveys the total sum of the grades (90 + 85 + 80) calculated by the program. This demonstrates that the code functions correctly and provides the expected result.

It’s like handing in your exam paper and receiving feedback from the teacher. The printed output is the feedback indicating how well you scored based on the answers you provided.

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