编写Java程序：录入5名学生百分制分数并生成表格及总分

Hey there! Let's build out your Java program to handle inputting scores for 5 students, display a formatted table, and calculate the total score. Here's the complete implementation along with clear explanations:

Complete Code #

import java.util.Scanner;

public class test33 {
    public static void main(String[] args) {
        Scanner kbReader = new Scanner(System.in);
        final int NUMBER_OF_STUDENTS = 5;
        int[] scores = new int[NUMBER_OF_STUDENTS];
        
        // Step 1: Prompt user to enter scores for each student
        for (int i = 0; i < NUMBER_OF_STUDENTS; i++) {
            System.out.printf("Enter score for Student No #%d (out of 100): ", i + 1);
            scores[i] = kbReader.nextInt();
        }
        
        // Step 2: Generate the summary table
        System.out.println("\n--- Student Score Summary ---");
        // Print table headers with aligned columns
        System.out.printf("%-15s %-20s%n", "Student No #", "Score(out of 100)");
        System.out.println("-----------------------------");
        
        // Print each student's data and calculate total score
        int totalScore = 0;
        for (int i = 0; i < NUMBER_OF_STUDENTS; i++) {
            System.out.printf("%-15d %-20d%n", i + 1, scores[i]);
            totalScore += scores[i];
        }
        
        // Display the total score
        System.out.println("-----------------------------");
        System.out.printf("%-15s %-20d%n", "Total", totalScore);
        
        kbReader.close();
    }
}

Key Breakdown of the Code #

• Input Collection: We use a for loop to cycle through each student, prompting for their score and storing it in an array. The NUMBER_OF_STUDENTS constant makes it easy to adjust the number of students later if needed.
• Clean Table Formatting: printf is used with format specifiers like %-15s to ensure left-aligned, fixed-width columns—this makes the table look organized and easy to read.
• Total Score Calculation: As we print each student's score, we accumulate the total in a variable, then display it at the bottom of the table for a quick summary.
• Resource Management: We close the Scanner at the end to avoid unnecessary resource leaks, which is a good practice for I/O classes.

Example Output #

If you input scores 55, 66, 77, 88, 99, the output will look like this:

Enter score for Student No #1 (out of 100): 55
Enter score for Student No #2 (out of 100): 66
Enter score for Student No #3 (out of 100): 77
Enter score for Student No #4 (out of 100): 88
Enter score for Student No #5 (out of 100): 99

--- Student Score Summary ---
Student No #     Score(out of 100)   
-----------------------------
1                55                  
2                66                  
3                77                  
4                88                  
5                99                  
-----------------------------
Total            385                 

Optional Enhancement: Input Validation #

If you want to ensure users only enter valid scores (0-100), you can modify the input loop to add a check:

for (int i = 0; i < NUMBER_OF_STUDENTS; i++) {
    int score;
    do {
        System.out.printf("Enter score for Student No #%d (out of 100): ", i + 1);
        score = kbReader.nextInt();
        if (score < 0 || score > 100) {
            System.out.println("Invalid score! Please enter a value between 0 and 100.");
        }
    } while (score < 0 || score > 100);
    scores[i] = score;
}

This prevents invalid entries and guides the user to input correct values.

内容的提问来源于stack exchange，提问作者عبدالله عبود